Merge feature/v1.3.2-lint-cleanup into main

- Complete lint cleanup (Phase 1-7)
- Replace magic numbers with constants
- Remove unused imports/members
- Add Logger.w() for swallowed exceptions
- Custom SyncException for better error handling
- ConstructorParameterNaming with @SerializedName
- ReturnCount & Destructuring with @Suppress
- F-Droid: Add privacy notice for file logging
- Update docs (FEATURES.md, README.md)
- Add fastlane changelogs for versionCode 10

.github/workflows/build-production-apk.yml

@@ -61,33 +61,15 @@ jobs:
         run: |
           mkdir -p apk-output
           
-          # === Standard Flavor (mit Google Services) ===
-          # Universal APK (funktioniert auf allen Geraeten)
-          cp android/app/build/outputs/apk/standard/release/app-standard-universal-release.apk \
-             apk-output/simple-notes-sync-v${{ env.VERSION_NAME }}-standard-universal.apk
+          # Standard Flavor - Universal APK
+          cp android/app/build/outputs/apk/standard/release/app-standard-release.apk \
+             apk-output/simple-notes-sync-v${{ env.VERSION_NAME }}-standard.apk
           
-          # ARM64 APK (moderne Geräte 2018+)
-          cp android/app/build/outputs/apk/standard/release/app-standard-arm64-v8a-release.apk \
-             apk-output/simple-notes-sync-v${{ env.VERSION_NAME }}-standard-arm64-v8a.apk
+          # F-Droid Flavor - Universal APK
+          cp android/app/build/outputs/apk/fdroid/release/app-fdroid-release.apk \
+             apk-output/simple-notes-sync-v${{ env.VERSION_NAME }}-fdroid.apk
           
-          # ARMv7 APK (ältere Geräte)
-          cp android/app/build/outputs/apk/standard/release/app-standard-armeabi-v7a-release.apk \
-             apk-output/simple-notes-sync-v${{ env.VERSION_NAME }}-standard-armeabi-v7a.apk
-          
-          # === F-Droid Flavor (ohne Google Services) ===
-          # Universal APK
-          cp android/app/build/outputs/apk/fdroid/release/app-fdroid-universal-release.apk \
-             apk-output/simple-notes-sync-v${{ env.VERSION_NAME }}-fdroid-universal.apk
-          
-          # ARM64 APK
-          cp android/app/build/outputs/apk/fdroid/release/app-fdroid-arm64-v8a-release.apk \
-             apk-output/simple-notes-sync-v${{ env.VERSION_NAME }}-fdroid-arm64-v8a.apk
-          
-          # ARMv7 APK
-          cp android/app/build/outputs/apk/fdroid/release/app-fdroid-armeabi-v7a-release.apk \
-             apk-output/simple-notes-sync-v${{ env.VERSION_NAME }}-fdroid-armeabi-v7a.apk
-          
-          echo "✅ APK-Dateien vorbereitet (Standard + F-Droid):"
+          echo "✅ APK-Dateien vorbereitet:"
           ls -lh apk-output/
       
       - name: APK-Artefakte hochladen
@@ -104,24 +86,22 @@ jobs:
       
       - name: F-Droid Changelogs lesen
         run: |
-          # Lese deutsche Changelog (Hauptsprache)
-          if [ -f "android/fastlane/metadata/android/de-DE/changelogs/${{ env.BUILD_NUMBER }}.txt" ]; then
-            {
-              echo 'CHANGELOG_DE<<EOF'
-              cat "android/fastlane/metadata/android/de-DE/changelogs/${{ env.BUILD_NUMBER }}.txt"
-              echo 'EOF'
-            } >> $GITHUB_ENV
+          # Lese deutsche Changelog (Hauptsprache) - Use printf to ensure proper formatting
+          if [ -f "fastlane/metadata/android/de-DE/changelogs/${{ env.BUILD_NUMBER }}.txt" ]; then
+            CHANGELOG_CONTENT=$(cat "fastlane/metadata/android/de-DE/changelogs/${{ env.BUILD_NUMBER }}.txt")
+            echo "CHANGELOG_DE<<GHADELIMITER" >> $GITHUB_ENV
+            echo "$CHANGELOG_CONTENT" >> $GITHUB_ENV
+            echo "GHADELIMITER" >> $GITHUB_ENV
           else
             echo "CHANGELOG_DE=Keine deutschen Release Notes verfügbar." >> $GITHUB_ENV
           fi
           
           # Lese englische Changelog (optional)
-          if [ -f "android/fastlane/metadata/android/en-US/changelogs/${{ env.BUILD_NUMBER }}.txt" ]; then
-            {
-              echo 'CHANGELOG_EN<<EOF'
-              cat "android/fastlane/metadata/android/en-US/changelogs/${{ env.BUILD_NUMBER }}.txt"
-              echo 'EOF'
-            } >> $GITHUB_ENV
+          if [ -f "fastlane/metadata/android/en-US/changelogs/${{ env.BUILD_NUMBER }}.txt" ]; then
+            CHANGELOG_CONTENT_EN=$(cat "fastlane/metadata/android/en-US/changelogs/${{ env.BUILD_NUMBER }}.txt")
+            echo "CHANGELOG_EN<<GHADELIMITER" >> $GITHUB_ENV
+            echo "$CHANGELOG_CONTENT_EN" >> $GITHUB_ENV
+            echo "GHADELIMITER" >> $GITHUB_ENV
           else
             echo "CHANGELOG_EN=" >> $GITHUB_ENV
           fi
@@ -140,25 +120,19 @@ jobs:
             
             | Variante | Datei | Info |
             |----------|-------|------|
-            | **🏆 Empfohlen** | `simple-notes-sync-v${{ env.VERSION_NAME }}-standard-universal.apk` | Funktioniert auf allen Android-Geraeten |
-            | Modern (2018+) | `simple-notes-sync-v${{ env.VERSION_NAME }}-standard-arm64-v8a.apk` | Kleinere Dateigröße fuer 64-bit Geräte |
-            | Aelter (<2018) | `simple-notes-sync-v${{ env.VERSION_NAME }}-standard-armeabi-v7a.apk` | Fuer 32-bit ARM Geräte |
-            | F-Droid Universal | `simple-notes-sync-v${{ env.VERSION_NAME }}-fdroid-universal.apk` | Fuer F-Droid Store |
-            | F-Droid ARM64 | `simple-notes-sync-v${{ env.VERSION_NAME }}-fdroid-arm64-v8a.apk` | F-Droid 64-bit |
-            | F-Droid ARMv7 | `simple-notes-sync-v${{ env.VERSION_NAME }}-fdroid-armeabi-v7a.apk` | F-Droid 32-bit |
-            
-            💡 **Nicht sicher?** → Nimm die **Universal** APK!
+            | **🏆 Empfohlen** | `simple-notes-sync-v${{ env.VERSION_NAME }}-standard.apk` | Standard-Version (funktioniert auf allen Geraeten) |
+            | F-Droid | `simple-notes-sync-v${{ env.VERSION_NAME }}-fdroid.apk` | Fuer F-Droid Store |
             
             ---
             
             ## 📋 Changelog / Release Notes
             
-            ${{ env.CHANGELOG_EN }}
+            ${{ env.CHANGELOG_DE }}
             
             <details>
-            <summary><EFBFBD>🇪 Deutsche Version (zum Aufklappen)</summary>
+            <summary>🌍 English Version</summary>
             
-            ${{ env.CHANGELOG_DE }}
+            ${{ env.CHANGELOG_EN }}
             
             </details>
             

CHANGELOG.md

@@ -0,0 +1,387 @@
+# Changelog
+
+All notable changes to Simple Notes Sync will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
+
+---
+
+## [1.3.2] - 2026-01-10
+
+### Changed
+- **🧹 Code-Qualität: "Clean Slate" Release**
+  - Alle einfachen Lint-Issues behoben (Phase 1-7 des Cleanup-Plans)
+  - Unused Imports und Members entfernt
+  - Magic Numbers durch benannte Konstanten ersetzt
+  - SwallowedExceptions mit Logger.w() versehen
+  - MaxLineLength-Verstöße reformatiert
+  - ConstructorParameterNaming (snake_case → camelCase mit @SerializedName)
+  - Custom Exceptions: SyncException.kt und ValidationException.kt erstellt
+
+### Added  
+- **📝 F-Droid Privacy Notice**
+  - Datenschutz-Hinweis für die Datei-Logging-Funktion
+  - Erklärt dass Logs nur lokal gespeichert werden
+  - Erfüllt F-Droid Opt-in Consent-Anforderungen
+
+### Technical Improvements
+- **⚡ Neue Konstanten für bessere Wartbarkeit**
+  - `SYNC_COMPLETED_DELAY_MS`, `ERROR_DISPLAY_DELAY_MS` (MainActivity)
+  - `CONNECTION_TIMEOUT_MS` (SettingsActivity)
+  - `SOCKET_TIMEOUT_MS`, `MAX_FILENAME_LENGTH`, `ETAG_PREVIEW_LENGTH` (WebDavSyncService)
+  - `AUTO_CANCEL_TIMEOUT_MS` (NotificationHelper)
+  - RFC 1918 IP-Range Konstanten (UrlValidator)
+  - `DAYS_THRESHOLD`, `TRUNCATE_SUFFIX_LENGTH` (Extensions)
+
+- **🔒 @Suppress Annotations für legitime Patterns**
+  - ReturnCount: Frühe Returns für Validierung sind idiomatisch
+  - LoopWithTooManyJumpStatements: Komplexe Sync-Logik dokumentiert
+
+### Notes
+- Komplexe Refactorings (LargeClass, LongMethod) für v1.3.3+ geplant
+- Deprecation-Warnungen (LocalBroadcastManager, ProgressDialog) bleiben bestehen
+
+---
+
+## [1.3.1] - 2026-01-08
+
+### Fixed
+- **🔧 Multi-Device JSON Sync (Danke an Thomas aus Bielefeld)**
+  - JSON-Dateien werden jetzt korrekt zwischen Geräten synchronisiert
+  - Funktioniert auch ohne aktiviertes Markdown
+  - Hybrid-Optimierung: Server-Timestamp (Primary) + E-Tag (Secondary) Checks
+  - E-Tag wird nach Upload gecached um Re-Download zu vermeiden
+
+### Performance Improvements
+- **⚡ JSON Sync Performance-Parität**
+  - JSON-Sync erreicht jetzt gleiche Performance wie Markdown (~2-3 Sekunden)
+  - Timestamp-basierte Skip-Logik für unveränderte Dateien (~500ms pro Datei gespart)
+  - E-Tag-Matching als Fallback für Dateien die seit letztem Sync modifiziert wurden
+  - **Beispiel:** 24 Dateien von 12-14s auf ~2.7s reduziert (keine Änderungen)
+
+- **⏭️ Skip unveränderte Dateien** (Haupt-Performance-Fix!)
+  - JSON-Dateien: Überspringt alle Notizen, die seit letztem Sync nicht geändert wurden
+  - Markdown-Dateien: Überspringt unveränderte MD-Dateien basierend auf Server-Timestamp
+  - **Spart ~500ms pro Datei** bei Nextcloud (~20 Dateien = 10 Sekunden gespart!)
+  - Von 21 Sekunden Sync-Zeit auf 2-3 Sekunden reduziert
+
+- **⚡ Session-Caching für WebDAV** 
+  - Sardine-Client wird pro Sync-Session wiederverwendet (~600ms gespart)
+  - WiFi-IP-Adresse wird gecacht statt bei jeder Anfrage neu ermittelt (~300ms gespart)
+  - `/notes/` Ordner-Existenz wird nur einmal pro Sync geprüft (~500ms gespart)
+  - **Gesamt: ~1.4 Sekunden zusätzlich gespart**
+
+- **📝 Content-basierte Markdown-Erkennung**
+  - Extern bearbeitete Markdown-Dateien werden auch erkannt wenn YAML-Timestamp nicht aktualisiert wurde
+  - Löst das Problem: Obsidian/Texteditor-Änderungen wurden nicht importiert
+  - Hybridansatz: Erst Timestamp-Check (schnell), dann Content-Vergleich (zuverlässig)
+
+### Added
+- **🔄 Sync-Status-Anzeige (UI)**
+  - Sichtbares Banner "Synchronisiere..." mit ProgressBar während Sync läuft
+  - Sync-Button und Pull-to-Refresh werden deaktiviert während Sync aktiv
+  - Verhindert versehentliche Doppel-Syncs durch visuelle Rückmeldung
+  - Auch in Einstellungen: "Jetzt synchronisieren" Button wird deaktiviert
+
+### Fixed
+- **🔧 Sync-Mutex verhindert doppelte Syncs**
+  - Keine doppelten Toast-Nachrichten mehr bei schnellem Pull-to-Refresh
+  - Concurrent Sync-Requests werden korrekt blockiert
+
+- **🐛 Lint-Fehler behoben**
+  - `View.generateViewId()` statt hardcodierte IDs in RadioButtons
+  - `app:tint` statt `android:tint` für AppCompat-Kompatibilität
+
+### Added
+- **🔍 detekt Code-Analyse**
+  - Statische Code-Analyse mit detekt 1.23.4 integriert
+  - Pragmatische Konfiguration für Sync-intensive Codebasis
+  - 91 Issues identifiziert (als Baseline für v1.4.0)
+
+- **🏗️ Debug Build mit separatem Package**
+  - Debug-APK kann parallel zur Release-Version installiert werden
+  - Package: `dev.dettmer.simplenotes.debug` (Debug) vs `dev.dettmer.simplenotes` (Release)
+  - App-Name zeigt "Simple Notes (Debug)" für einfache Unterscheidung
+
+- **📊 Debug-Logging UI**
+  - Neuer "Debug Log" Button in Einstellungen → Erweitert
+  - Zeigt letzte Sync-Logs mit Zeitstempeln
+  - Export-Funktion für Fehlerberichte
+
+### Technical
+- `WebDavSyncService`: Hybrid-Optimierung für JSON-Downloads (Timestamp PRIMARY, E-Tag SECONDARY)
+- `WebDavSyncService`: E-Tag refresh nach Upload statt Invalidierung (verhindert Re-Download)
+- E-Tag Caching: `SharedPreferences` mit Key-Pattern `etag_json_{noteId}`
+- Skip-Logik: `if (serverModified <= lastSync) skip` → ~1ms pro Datei
+- Fallback E-Tag: `if (serverETag == cachedETag) skip` → für Dateien modifiziert nach lastSync
+- PROPFIND nach PUT: Fetch E-Tag nach Upload für korrektes Caching
+- `SyncStateManager`: Neuer Singleton mit `StateFlow<Boolean>` für Sync-Status
+- `MainActivity`: Observer auf `SyncStateManager.isSyncing` für UI-Updates
+- Layout: `sync_status_banner` mit `ProgressBar` + `TextView`
+- `WebDavSyncService`: Skip-Logik für unveränderte JSON/MD Dateien basierend auf `lastSyncTimestamp`
+- `WebDavSyncService`: Neue Session-Cache-Variablen (`sessionSardine`, `sessionWifiAddress`, `notesDirEnsured`)
+- `getOrCreateSardine()`: Cached Sardine-Client mit automatischer Credentials-Konfiguration
+- `getOrCacheWiFiAddress()`: WiFi-Adresse wird nur einmal pro Sync ermittelt
+- `clearSessionCache()`: Aufräumen am Ende jeder Sync-Session
+- `ensureNotesDirectoryExists()`: Cached Directory-Check
+- Content-basierter Import: Vergleicht MD-Content mit lokaler Note wenn Timestamps gleich
+- Build-Tooling: detekt aktiviert, ktlint vorbereitet (deaktiviert wegen Parser-Problemen)
+- Debug BuildType: `applicationIdSuffix = ".debug"`, `versionNameSuffix = "-debug"`
+
+---
+
+## [1.3.0] - 2026-01-07
+
+### Added
+- **🚀 Multi-Device Sync** (Thanks to Thomas from Bielefeld for reporting!)
+  - Automatic download of new notes from other devices
+  - Deletion tracking prevents "zombie notes" (deleted notes don't come back)
+  - Smart cleanup: Re-created notes (newer timestamp) are downloaded
+  - Works with all devices: v1.2.0, v1.2.1, v1.2.2, and v1.3.0
+
+- **🗑️ Server Deletion via Swipe Gesture**
+  - Swipe left on notes to delete from server (requires confirmation)
+  - Prevents duplicate notes on other devices
+  - Works with deletion tracking system
+  - Material Design confirmation dialog
+
+- **⚡ E-Tag Performance Optimization**
+  - Smart server checking with E-Tag caching (~150ms vs 3000ms for "no changes")
+  - 20x faster when server has no updates
+  - E-Tag hybrid approach: E-Tag for JSON (fast), timestamp for Markdown (reliable)
+  - Battery-friendly with minimal server requests
+
+- **📥 Markdown Auto-Sync Toggle**
+  - NEW: Unified Auto-Sync toggle in Settings (replaces separate Export/Auto-Import toggles)
+  - When enabled: Notes export to Markdown AND import changes automatically
+  - When disabled: Manual sync button appears for on-demand synchronization
+  - Performance: Auto-Sync OFF = 0ms overhead
+
+- **🔘 Manual Markdown Sync Button**
+  - Manual sync button for performance-conscious users
+  - Shows import/export counts after completion
+  - Only visible when Auto-Sync is disabled
+  - On-demand synchronization (~150-200ms only when triggered)
+
+- **⚙️ Server-Restore Modes**
+  - MERGE: Keep local notes + add server notes
+  - REPLACE: Delete all local + download from server
+  - OVERWRITE: Update duplicates, keep non-duplicates
+  - Restore modes now work correctly for WebDAV restore
+
+### Technical
+- New `DeletionTracker` model with JSON persistence
+- `NotesStorage`: Added deletion tracking methods
+- `WebDavSyncService.hasUnsyncedChanges()`: Intelligent server checks with E-Tag caching
+- `WebDavSyncService.downloadRemoteNotes()`: Deletion-aware downloads
+- `WebDavSyncService.restoreFromServer()`: Support for restore modes
+- `WebDavSyncService.deleteNoteFromServer()`: Server deletion with YAML frontmatter scanning
+- `WebDavSyncService.importMarkdownFiles()`: Automatic Markdown import during sync
+- `WebDavSyncService.manualMarkdownSync()`: Manual sync with result counts
+- `MainActivity.setupSwipeToDelete()`: Two-stage swipe deletion with confirmation
+- E-Tag caching in SharedPreferences for performance
+
+---
+
+## [1.2.2] - 2026-01-06
+
+### Fixed
+- **Backward Compatibility for v1.2.0 Users (Critical)**
+  - App now reads BOTH old (Root) AND new (`/notes/`) folder structures
+  - Users upgrading from v1.2.0 no longer lose their existing notes
+  - Server-Restore now finds notes from v1.2.0 stored in Root folder
+  - Automatic deduplication prevents loading the same note twice
+  - Graceful error handling if Root folder is not accessible
+
+### Technical
+- `WebDavSyncService.downloadRemoteNotes()` - Dual-mode download (Root + /notes/)
+- `WebDavSyncService.restoreFromServer()` - Now uses dual-mode download
+- Migration happens naturally: new uploads go to `/notes/`, old notes stay readable
+
+---
+
+## [1.2.1] - 2026-01-05
+
+### Fixed
+- **Markdown Initial Export Bugfix**
+  - Existing notes are now exported as Markdown when Desktop Integration is activated
+  - Previously, only new notes created after activation were exported
+  - Progress dialog shows export status with current/total counter
+  - Error handling for network issues during export
+  - Individual note failures don't abort the entire export
+
+- **Markdown Directory Structure Fix**
+  - Markdown files now correctly land in `/notes-md/` folder
+  - Smart URL detection supports both Root-URL and `/notes` URL structures
+  - Previously, MD files were incorrectly placed in the root directory
+  - Markdown import now finds files correctly
+
+- **JSON URL Normalization**
+  - Simplified server configuration: enter only base URL (e.g., `http://server:8080/`)
+  - App automatically creates `/notes/` for JSON files and `/notes-md/` for Markdown
+  - Smart detection: both `http://server:8080/` and `http://server:8080/notes/` work correctly
+  - Backward compatible: existing setups with `/notes` in URL continue to work
+  - No migration required for existing users
+
+### Changed
+- **Markdown Directory Creation**
+  - `notes-md/` folder is now created on first sync (regardless of Desktop Integration setting)
+  - Prevents 404 errors when mounting WebDAV folder
+  - Better user experience: folder is visible before enabling the feature
+
+- **Settings UI Improvements**
+  - Updated example URL from `/webdav` to `/notes` to match app behavior
+  - Example now shows: `http://192.168.0.188:8080/notes`
+
+### Technical
+- `WebDavSyncService.ensureMarkdownDirectoryExists()` - Creates MD folder early
+- `WebDavSyncService.getMarkdownUrl()` - Smart URL detection for both structures
+- `WebDavSyncService.exportAllNotesToMarkdown()` - Exports all local notes with progress callback
+- `SettingsActivity.onMarkdownExportToggled()` - Triggers initial export with ProgressDialog
+
+---
+
+## [1.2.0] - 2026-01-04
+
+### Added
+- **Local Backup System**
+  - Export all notes as JSON file to any location (Downloads, SD card, cloud folder)
+  - Import backup with 3 modes: Merge, Replace, or Overwrite duplicates
+  - Automatic safety backup created before every restore
+  - Backup validation (format and version check)
+  
+- **Markdown Desktop Integration**
+  - Optional Markdown export parallel to JSON sync
+  - `.md` files synced to `notes-md/` folder on WebDAV
+  - YAML frontmatter with `id`, `created`, `updated`, `device`
+  - Manual import button to pull Markdown changes from server
+  - Last-Write-Wins conflict resolution via timestamps
+  
+- **Settings UI Extensions**
+  - New "Backup & Restore" section with local + server restore
+  - New "Desktop Integration" section with Markdown toggle
+  - Universal restore dialog with radio button mode selection
+
+### Changed
+- **Server Restore Behavior**: Users now choose restore mode (Merge/Replace/Overwrite) instead of hard-coded replace-all
+
+### Technical
+- `BackupManager.kt` - Complete backup/restore logic
+- `Note.toMarkdown()` / `Note.fromMarkdown()` - Markdown conversion with YAML frontmatter
+- `WebDavSyncService` - Extended for dual-format sync (JSON master + Markdown mirror)
+- ISO8601 timestamp formatting for desktop compatibility
+- Filename sanitization for safe Markdown file names
+
+### Documentation
+- Added WebDAV mount instructions (Windows, macOS, Linux)
+- Created [SYNC_ARCHITECTURE.md](../project-docs/simple-notes-sync/architecture/SYNC_ARCHITECTURE.md) - Complete sync documentation
+- Created [MARKDOWN_DESKTOP_REALITY_CHECK.md](../project-docs/simple-notes-sync/markdown-desktop-plan/MARKDOWN_DESKTOP_REALITY_CHECK.md) - Desktop integration analysis
+
+---
+
+## [1.1.2] - 2025-12-28
+
+### Fixed
+- **"Job was cancelled" Error**
+  - Fixed coroutine cancellation in sync worker
+  - Proper error handling for interrupted syncs
+  
+- **UI Improvements**
+  - Back arrow instead of X in note editor (better UX)
+  - Pull-to-refresh for manual sync trigger
+  - HTTP/HTTPS protocol selection with radio buttons
+  - Inline error display (no toast spam)
+  
+- **Performance & Battery**
+  - Sync only on actual changes (saves battery)
+  - Auto-save notifications removed
+  - 24-hour server offline warning instead of instant error
+  
+### Changed
+- Settings grouped into "Auto-Sync" and "Sync Interval" sections
+- HTTP only allowed for local networks (RFC 1918 IPs)
+- Swipe-to-delete without UI flicker
+
+---
+
+## [1.1.1] - 2025-12-27
+
+### Fixed
+- **WiFi Connect Sync**
+  - No error notifications in foreign WiFi networks
+  - Server reachability check before sync (2s timeout)
+  - Silent abort when server offline
+  - Pre-check waits until network is ready
+  - No errors during network initialization
+  
+### Changed
+- **Notifications**
+  - Old sync notifications cleared on app start
+  - Error notifications auto-dismiss after 30 seconds
+  
+### UI
+- Sync icon only shown when sync is configured
+- Swipe-to-delete without flicker
+- Scroll to top after saving note
+
+### Technical
+- Server check with 2-second timeout before sync attempts
+- Network readiness check in WiFi connect trigger
+- Notification cleanup on MainActivity.onCreate()
+
+---
+
+## [1.1.0] - 2025-12-26
+
+### Added
+- **Configurable Sync Intervals**
+  - User choice: 15, 30, or 60 minutes
+  - Real-world battery impact displayed (15min: ~0.8%/day, 30min: ~0.4%/day, 60min: ~0.2%/day)
+  - Radio button selection in settings
+  - Doze Mode optimization (syncs batched in maintenance windows)
+  
+- **About Section**
+  - App version from BuildConfig
+  - Links to GitHub repository and developer profile
+  - MIT license information
+  - Material 3 card design
+
+### Changed
+- Settings UI redesigned with grouped sections
+- Periodic sync updated dynamically when interval changes
+- WorkManager uses selected interval for background sync
+
+### Removed
+- Debug/Logs section from settings (cleaner UI)
+
+### Technical
+- `PREF_SYNC_INTERVAL_MINUTES` preference key
+- NetworkMonitor reads interval from SharedPreferences
+- `ExistingPeriodicWorkPolicy.UPDATE` for live interval changes
+
+---
+
+## [1.0.0] - 2025-12-25
+
+### Added
+- Initial release
+- WebDAV synchronization
+- Note creation, editing, deletion
+- 6 sync triggers:
+  - Periodic sync (configurable interval)
+  - App start sync
+  - WiFi connect sync
+  - Manual sync (menu button)
+  - Pull-to-refresh
+  - Settings "Sync Now" button
+- Material 3 design
+- Light/Dark theme support
+- F-Droid compatible (100% FOSS)
+
+---
+
+[1.2.0]: https://github.com/inventory69/simple-notes-sync/releases/tag/v1.2.0
+[1.1.2]: https://github.com/inventory69/simple-notes-sync/releases/tag/v1.1.2
+[1.1.1]: https://github.com/inventory69/simple-notes-sync/releases/tag/v1.1.1
+[1.1.0]: https://github.com/inventory69/simple-notes-sync/releases/tag/v1.1.0
+[1.0.0]: https://github.com/inventory69/simple-notes-sync/releases/tag/v1.0.0

QUICKSTART.en.md

@@ -76,7 +76,9 @@ ip addr show | grep "inet " | grep -v 127.0.0.1
    | **Password** | (your password from `.env`) |
    | **Gateway SSID** | Name of your WiFi network |
 
-4. **Press "Test connection"**
+   > **💡 Note:** Enter only the base URL (without `/notes`). The app automatically creates `/notes/` for JSON files and `/notes-md/` for Markdown export.
+
+4. **Press "Test connection"****
    - ✅ Success? → Continue to step 4
    - ❌ Error? → See [Troubleshooting](#troubleshooting)
 

QUICKSTART.md

@@ -76,6 +76,8 @@ ip addr show | grep "inet " | grep -v 127.0.0.1
    | **Passwort** | (dein Passwort aus `.env`) |
    | **Gateway SSID** | Name deines WLAN-Netzwerks |
 
+   > **💡 Hinweis:** Gib nur die Base-URL ein (ohne `/notes`). Die App erstellt automatisch `/notes/` für JSON-Dateien und `/notes-md/` für Markdown-Export.
+
 4. **"Verbindung testen"** drücken
    - ✅ Erfolg? → Weiter zu Schritt 4
    - ❌ Fehler? → Siehe [Troubleshooting](#troubleshooting)

README.en.md

@@ -6,7 +6,9 @@
 [![Material Design 3](https://img.shields.io/badge/Material-Design%203-green.svg)](https://m3.material.io/)
 [![License](https://img.shields.io/badge/License-MIT-yellow.svg)](LICENSE)
 
-**📱 [APK Download](https://github.com/inventory69/simple-notes-sync/releases/latest)** · **📖 [Documentation](DOCS.en.md)** · **🚀 [Quick Start](QUICKSTART.en.md)**
+[<img src="https://gitlab.com/IzzyOnDroid/repo/-/raw/master/assets/IzzyOnDroid.png" alt="Get it on IzzyOnDroid" height="80">](https://apt.izzysoft.de/fdroid/index/apk/dev.dettmer.simplenotes)
+
+**📱 [APK Download](https://github.com/inventory69/simple-notes-sync/releases/latest)** · **📖 [Documentation](docs/DOCS.en.md)** · **🚀 [Quick Start](QUICKSTART.en.md)**
 
 **🌍 Languages:** [Deutsch](README.md) · **English**
 
@@ -22,42 +24,27 @@
 
 ---
 
-## Features
+## ✨ Highlights
 
-### 📝 Notes
-- Create and edit simple text notes
-- Automatic save
-- Swipe-to-delete with confirmation
+- 📝 **Offline-first** - Works without internet
+- 🔄 **Auto-sync** - Home WiFi only (15/30/60 min)
+- 🔒 **Self-hosted** - Your data stays with you (WebDAV)
+- 💾 **Local backup** - Export/Import as JSON file
+- 🖥️ **Desktop integration** - Markdown export for VS Code, Typora, etc.
+- 🔋 **Battery-friendly** - ~0.2-0.8% per day
+- 🎨 **Material Design 3** - Dark mode & dynamic colors
 
-### 🔄 Synchronization
-- Auto-sync (15/30/60 min intervals)
-- WiFi-based - Sync on home WiFi connection
-- Server check (2s timeout) - No errors in foreign networks
-- Conflict-free merging via timestamps
-
-### 🏠 Self-Hosted & Privacy
-- WebDAV server (Nextcloud, ownCloud, etc.)
-- Your data stays with you - No tracking, no analytics
-- 100% Open Source (MIT license)
-
-### 🔋 Performance
-- Battery-friendly (~0.2-0.8% per day)
-- Doze Mode optimized
-- Offline-first - All features work without internet
-
-### 🎨 Material Design 3
-- Dynamic Colors (Material You)
-- Dark Mode
-- Modern, intuitive UI
+➡️ **Complete feature list:** [FEATURES.en.md](docs/FEATURES.en.md)
 
 ---
 
 ## 🚀 Quick Start
 
-### 1. Server Setup
+### 1. Server Setup (5 minutes)
 
 ```bash
-cd server
+git clone https://github.com/inventory69/simple-notes-sync.git
+cd simple-notes-sync/server
 cp .env.example .env
 # Set password in .env
 docker compose up -d
@@ -65,23 +52,30 @@ docker compose up -d
 
 ➡️ **Details:** [Server Setup Guide](server/README.en.md)
 
-### 2. App Installation
+### 2. App Installation (2 minutes)
 
 1. [Download APK](https://github.com/inventory69/simple-notes-sync/releases/latest)
 2. Install & open
-3. ⚙️ Settings → Configure server
-4. Enable auto-sync
+3. ⚙️ Settings → Configure server:
+   - **URL:** `http://YOUR-SERVER-IP:8080/` _(base URL only!)_
+   - **User:** `noteuser`
+   - **Password:** _(from .env)_
+   - **WiFi:** _(your network name)_
+4. **Test connection** → Enable auto-sync
+5. Done! 🎉
 
-➡️ **Details:** [Complete guide](QUICKSTART.en.md)
+➡️ **Detailed guide:** [QUICKSTART.en.md](QUICKSTART.en.md)
 
 ---
 
 ## 📚 Documentation
 
-- **[Quick Start Guide](QUICKSTART.en.md)** - Step-by-step guide for end users
-- **[Server Setup](server/README.en.md)** - Configure WebDAV server
-- **[Complete Docs](DOCS.en.md)** - Features, troubleshooting, build instructions
-
+| Document | Content |
+|----------|---------|
+| **[QUICKSTART.en.md](QUICKSTART.en.md)** | Step-by-step installation |
+| **[FEATURES.en.md](docs/FEATURES.en.md)** | Complete feature list |
+| **[BACKUP.en.md](docs/BACKUP.en.md)** | Backup & restore guide |
+| **[DESKTOP.en.md](docs/DESKTOP.en.md)** | Desktop integration (Markdown) |
 ---
 
 ## 🛠️ Development
@@ -91,13 +85,13 @@ cd android
 ./gradlew assembleStandardRelease
 ```
 
-➡️ **Details:** [Build instructions in DOCS.en.md](DOCS.en.md)
+➡️ **Build guide:** [DOCS.en.md](docs/DOCS.en.md#-build--deployment)
 
 ---
 
 ## 🤝 Contributing
 
-Contributions are welcome! See [CONTRIBUTING.md](CONTRIBUTING.md) for details.
+Contributions welcome! See [CONTRIBUTING.md](CONTRIBUTING.md)
 
 ---
 
@@ -105,4 +99,6 @@ Contributions are welcome! See [CONTRIBUTING.md](CONTRIBUTING.md) for details.
 
 MIT License - see [LICENSE](LICENSE)
 
-**v1.1.1** · Built with Kotlin + Material Design 3
+---
+
+**v1.3.2** · Built with ❤️ using Kotlin + Material Design 3

README.md

@@ -6,7 +6,9 @@
 [![Material Design 3](https://img.shields.io/badge/Material-Design%203-green.svg)](https://m3.material.io/)
 [![License](https://img.shields.io/badge/License-MIT-yellow.svg)](LICENSE)
 
-**📱 [APK Download](https://github.com/inventory69/simple-notes-sync/releases/latest)** · **📖 [Dokumentation](DOCS.md)** · **🚀 [Quick Start](QUICKSTART.md)**
+[<img src="https://gitlab.com/IzzyOnDroid/repo/-/raw/master/assets/IzzyOnDroid.png" alt="Get it on IzzyOnDroid" height="80">](https://apt.izzysoft.de/fdroid/index/apk/dev.dettmer.simplenotes)
+
+**📱 [APK Download](https://github.com/inventory69/simple-notes-sync/releases/latest)** · **📖 [Dokumentation](docs/DOCS.md)** · **🚀 [Quick Start](QUICKSTART.md)**
 
 **🌍 Sprachen:** **Deutsch** · [English](README.en.md)
 
@@ -22,42 +24,27 @@
 
 ---
 
-## Features
+## ✨ Highlights
 
-### 📝 Notizen
-- Einfache Textnotizen erstellen und bearbeiten
-- Automatisches Speichern
-- Swipe-to-Delete mit Bestätigung
+- 📝 **Offline-First** - Funktioniert ohne Internet
+- 🔄 **Auto-Sync** - Nur im Heim-WLAN (15/30/60 Min)
+- 🔒 **Self-Hosted** - Deine Daten bleiben bei dir (WebDAV)
+- 💾 **Lokales Backup** - Export/Import als JSON-Datei
+- 🖥️ **Desktop-Integration** - Markdown-Export für VS Code, Typora, etc.
+- 🔋 **Akkuschonend** - ~0.2-0.8% pro Tag
+- 🎨 **Material Design 3** - Dark Mode & Dynamic Colors
 
-### 🔄 Synchronisation
-- Auto-Sync (15/30/60 Min Intervalle)
-- WiFi-basiert - Sync bei Heim-WLAN-Verbindung
-- Server-Check (2s Timeout) - Keine Fehler in fremden Netzwerken
-- Konfliktfreies Merging via Timestamps
-
-### 🏠 Self-Hosted & Privacy
-- WebDAV-Server (Nextcloud, ownCloud, etc.)
-- Deine Daten bei dir - Kein Tracking, keine Analytics
-- 100% Open Source (MIT Lizenz)
-
-### 🔋 Performance
-- Akkuschonend (~0.2-0.8% pro Tag)
-- Doze Mode optimiert
-- Offline-First - Alle Features ohne Internet
-
-### 🎨 Material Design 3
-- Dynamic Colors (Material You)
-- Dark Mode
-- Moderne, intuitive UI
+➡️ **Vollständige Feature-Liste:** [FEATURES.md](docs/FEATURES.md)
 
 ---
 
-## 🚀 Quick Start
+## 🚀 Schnellstart
 
-### 1. Server Setup
+### 1. Server Setup (5 Minuten)
 
 ```bash
-cd server
+git clone https://github.com/inventory69/simple-notes-sync.git
+cd simple-notes-sync/server
 cp .env.example .env
 # Passwort in .env setzen
 docker compose up -d
@@ -65,22 +52,32 @@ docker compose up -d
 
 ➡️ **Details:** [Server Setup Guide](server/README.md)
 
-### 2. App Installation
+### 2. App Installation (2 Minuten)
 
 1. [APK herunterladen](https://github.com/inventory69/simple-notes-sync/releases/latest)
 2. Installieren & öffnen
-3. ⚙️ Einstellungen → Server konfigurieren
-4. Auto-Sync aktivieren
+3. ⚙️ Einstellungen → Server konfigurieren:
+   - **URL:** `http://DEINE-SERVER-IP:8080/` _(nur Base-URL!)_
+   - **User:** `noteuser`
+   - **Passwort:** _(aus .env)_
+   - **WLAN:** _(dein Netzwerk-Name)_
+4. **Verbindung testen** → Auto-Sync aktivieren
+5. Fertig! 🎉
 
-➡️ **Details:** [Vollständige Anleitung](QUICKSTART.md)
+➡️ **Ausführliche Anleitung:** [QUICKSTART.md](QUICKSTART.md)
 
 ---
 
 ## 📚 Dokumentation
 
-- **[Quick Start Guide](QUICKSTART.md)** - Schritt-für-Schritt Anleitung für Endbenutzer
-- **[Server Setup](server/README.md)** - WebDAV Server konfigurieren
-- **[Vollständige Docs](DOCS.md)** - Features, Troubleshooting, Build-Anleitung
+| Dokument | Inhalt |
+|----------|--------|
+| **[QUICKSTART.md](QUICKSTART.md)** | Schritt-für-Schritt Installation |
+| **[FEATURES.md](docs/FEATURES.md)** | Vollständige Feature-Liste |
+| **[BACKUP.md](docs/BACKUP.md)** | Backup & Wiederherstellung |
+| **[DESKTOP.md](docs/DESKTOP.md)** | Desktop-Integration (Markdown) |
+| **[DOCS.md](docs/DOCS.md)** | Technische Details & Troubleshooting |
+| **[CHANGELOG.md](CHANGELOG.md)** | Versionshistorie |
 
 ---
 
@@ -91,13 +88,13 @@ cd android
 ./gradlew assembleStandardRelease
 ```
 
-➡️ **Details:** [Build-Anleitung in DOCS.md](DOCS.md)
+➡️ **Build-Anleitung:** [DOCS.md](docs/DOCS.md#-build--deployment)
 
 ---
 
 ## 🤝 Contributing
 
-Beiträge sind willkommen! Siehe [CONTRIBUTING.md](CONTRIBUTING.md) für Details.
+Beiträge willkommen! Siehe [CONTRIBUTING.md](CONTRIBUTING.md)
 
 ---
 
@@ -105,4 +102,6 @@ Beiträge sind willkommen! Siehe [CONTRIBUTING.md](CONTRIBUTING.md) für Details
 
 MIT License - siehe [LICENSE](LICENSE)
 
-**v1.1.1** · Gebaut mit Kotlin + Material Design 3
+---
+
+**v1.3.2** · Built with ❤️ using Kotlin + Material Design 3

android/.editorconfig

@@ -0,0 +1,61 @@
+# ⚡ v1.3.1: EditorConfig for ktlint
+# https://editorconfig.org
+
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+indent_size = 4
+indent_style = space
+insert_final_newline = true
+max_line_length = 120
+trim_trailing_whitespace = true
+
+[*.{kt,kts}]
+# ktlint rules
+ktlint_code_style = android_studio
+ktlint_standard_no-wildcard-imports = disabled
+ktlint_standard_package-name = enabled
+ktlint_standard_filename = enabled
+ktlint_standard_class-naming = enabled
+ktlint_standard_function-naming = enabled
+ktlint_standard_property-naming = enabled
+ktlint_standard_backing-property-naming = enabled
+ktlint_standard_enum-entry-name-case = enabled
+ktlint_standard_multiline-if-else = enabled
+ktlint_standard_no-empty-class-body = enabled
+ktlint_standard_no-empty-first-line-in-class-body = enabled
+ktlint_standard_blank-line-before-declaration = enabled
+ktlint_standard_context-receiver-wrapping = enabled
+ktlint_standard_function-expression-body = disabled
+ktlint_standard_function-literal = enabled
+ktlint_standard_function-type-modifier-spacing = enabled
+ktlint_standard_kdoc-wrapping = enabled
+ktlint_standard_modifier-list-spacing = enabled
+ktlint_standard_no-blank-line-in-list = enabled
+ktlint_standard_no-consecutive-comments = disabled
+ktlint_standard_no-single-line-block-comment = enabled
+ktlint_standard_parameter-list-spacing = enabled
+ktlint_standard_parameter-list-wrapping = enabled
+ktlint_standard_property-wrapping = enabled
+ktlint_standard_spacing-between-function-name-and-opening-parenthesis = enabled
+ktlint_standard_statement-wrapping = enabled
+ktlint_standard_string-template-indent = disabled
+ktlint_standard_try-catch-finally-spacing = enabled
+ktlint_standard_type-argument-list-spacing = enabled
+ktlint_standard_type-parameter-list-spacing = enabled
+ktlint_standard_value-argument-comment = enabled
+ktlint_standard_value-parameter-comment = enabled
+
+[*.md]
+trim_trailing_whitespace = false
+
+[*.{xml,json}]
+indent_size = 2
+
+[*.yml]
+indent_size = 2
+
+[Makefile]
+indent_style = tab

android/app/build.gradle.kts

@@ -1,6 +1,9 @@
 plugins {
     alias(libs.plugins.android.application)
     alias(libs.plugins.kotlin.android)
+    // ⚡ v1.3.1: ktlint deaktiviert wegen Parser-Problemen, aktivieren in v1.4.0
+    // alias(libs.plugins.ktlint)
+    alias(libs.plugins.detekt)
 }
 
 import java.util.Properties
@@ -17,8 +20,8 @@ android {
         applicationId = "dev.dettmer.simplenotes"
         minSdk = 24
         targetSdk = 36
-        versionCode = 4  // 🔥 v1.1.2: UX Fixes + CancellationException Handling
-        versionName = "1.1.2"  // 🔥 v1.1.2: Better UX + Job Cancellation Fix
+        versionCode = 10  // 🚀 v1.3.2: Lint-Cleanup "Clean Slate"
+        versionName = "1.3.2"  // 🚀 v1.3.2: Code-Qualität-Release (alle einfachen Lint-Issues behoben)
 
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
         
@@ -32,23 +35,15 @@ android {
         includeInBundle = false  // Also disable for AAB (Google Play)
     }
     
-    // Enable multiple APKs per ABI for smaller downloads
-    splits {
-        abi {
-            isEnable = true
-            reset()
-            include("armeabi-v7a", "arm64-v8a")
-            isUniversalApk = true  // Also generate universal APK
-        }
-    }
-    
     // Product Flavors for F-Droid and standard builds
+    // Note: APK splits are disabled to ensure single APK output
     flavorDimensions += "distribution"
     productFlavors {
         create("fdroid") {
             dimension = "distribution"
             // F-Droid builds have no proprietary dependencies
             // All dependencies in this project are already FOSS-compatible
+            // No APK splits - F-Droid expects single universal APK
         }
         
         create("standard") {
@@ -75,6 +70,16 @@ android {
     }
 
     buildTypes {
+        debug {
+            // ⚡ v1.3.1: Debug-Builds können parallel zur Release-App installiert werden
+            applicationIdSuffix = ".debug"
+            versionNameSuffix = "-debug"
+            isDebuggable = true
+            
+            // Optionales separates Icon-Label für Debug-Builds
+            resValue("string", "app_name_debug", "Simple Notes (Debug)")
+        }
+        
         release {
             isMinifyEnabled = true
             isShrinkResources = true
@@ -144,3 +149,27 @@ fun getBuildDate(): String {
     val dateFormat = SimpleDateFormat("yyyy-MM-dd", Locale.US)
     return dateFormat.format(Date())
 }
+
+// ⚡ v1.3.1: ktlint deaktiviert wegen Parser-Problemen
+// Aktivieren in v1.4.0 wenn Code-Stil bereinigt wurde
+// ktlint {
+//     android = true
+//     outputToConsole = true
+//     ignoreFailures = true
+//     enableExperimentalRules = false
+//     filter {
+//         exclude("**/generated/**")
+//         exclude("**/build/**")
+//     }
+// }
+
+// ⚡ v1.3.1: detekt-Konfiguration
+detekt {
+    buildUponDefaultConfig = true
+    allRules = false
+    config.setFrom(files("$rootDir/config/detekt/detekt.yml"))
+    baseline = file("$rootDir/config/detekt/baseline.xml")
+    
+    // Parallel-Verarbeitung für schnellere Checks
+    parallel = true
+}

android/app/src/main/java/dev/dettmer/simplenotes/MainActivity.kt

@@ -21,20 +21,29 @@ import com.google.android.material.color.DynamicColors
 import com.google.android.material.floatingactionbutton.FloatingActionButton
 import com.google.android.material.snackbar.Snackbar
 import com.google.android.material.card.MaterialCardView
+import com.google.android.material.dialog.MaterialAlertDialogBuilder
 import dev.dettmer.simplenotes.adapters.NotesAdapter
+import dev.dettmer.simplenotes.models.Note
 import dev.dettmer.simplenotes.storage.NotesStorage
 import dev.dettmer.simplenotes.sync.SyncWorker
 import dev.dettmer.simplenotes.utils.NotificationHelper
 import dev.dettmer.simplenotes.utils.showToast
 import dev.dettmer.simplenotes.utils.Constants
 import android.widget.TextView
+import android.widget.CheckBox
+import android.widget.Toast
+import androidx.lifecycle.lifecycleScope
+import kotlinx.coroutines.launch
 import androidx.lifecycle.lifecycleScope
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import dev.dettmer.simplenotes.sync.WebDavSyncService
+import dev.dettmer.simplenotes.sync.SyncStateManager
 import androidx.core.splashscreen.SplashScreen.Companion.installSplashScreen
 import androidx.swiperefreshlayout.widget.SwipeRefreshLayout
+import android.view.View
+import android.widget.LinearLayout
 
 class MainActivity : AppCompatActivity() {
     
@@ -44,9 +53,16 @@ class MainActivity : AppCompatActivity() {
     private lateinit var toolbar: MaterialToolbar
     private lateinit var swipeRefreshLayout: SwipeRefreshLayout
     
+    // 🔄 v1.3.1: Sync Status Banner
+    private lateinit var syncStatusBanner: LinearLayout
+    private lateinit var syncStatusText: TextView
+    
     private lateinit var adapter: NotesAdapter
     private val storage by lazy { NotesStorage(this) }
     
+    // Menu reference for sync button state
+    private var optionsMenu: Menu? = null
+    
     // Track pending deletions to prevent flicker when notes reload
     private val pendingDeletions = mutableSetOf<String>()
     
@@ -60,6 +76,8 @@ class MainActivity : AppCompatActivity() {
         private const val REQUEST_SETTINGS = 1002
         private const val MIN_AUTO_SYNC_INTERVAL_MS = 60_000L // 1 Minute
         private const val PREF_LAST_AUTO_SYNC_TIME = "last_auto_sync_timestamp"
+        private const val SYNC_COMPLETED_DELAY_MS = 1500L
+        private const val ERROR_DISPLAY_DELAY_MS = 3000L
     }
     
     /**
@@ -91,9 +109,10 @@ class MainActivity : AppCompatActivity() {
         
         setContentView(R.layout.activity_main)
         
-        // File Logging aktivieren wenn eingestellt
-        if (prefs.getBoolean("file_logging_enabled", false)) {
-            Logger.enableFileLogging(this)
+        // Logger initialisieren und File-Logging aktivieren wenn eingestellt
+        Logger.init(this)
+        if (prefs.getBoolean(Constants.KEY_FILE_LOGGING_ENABLED, false)) {
+            Logger.setFileLoggingEnabled(true)
         }
         
         // Alte Sync-Notifications beim App-Start löschen
@@ -110,6 +129,65 @@ class MainActivity : AppCompatActivity() {
         setupFab()
         
         loadNotes()
+        
+        // 🔄 v1.3.1: Observe sync state for UI updates
+        setupSyncStateObserver()
+    }
+    
+    /**
+     * 🔄 v1.3.1: Beobachtet Sync-Status für UI-Feedback
+     */
+    private fun setupSyncStateObserver() {
+        SyncStateManager.syncStatus.observe(this) { status ->
+            when (status.state) {
+                SyncStateManager.SyncState.SYNCING -> {
+                    // Disable sync controls
+                    setSyncControlsEnabled(false)
+                    // 🔄 v1.3.1: Show sync status banner (ersetzt SwipeRefresh-Animation)
+                    syncStatusText.text = getString(R.string.sync_status_syncing)
+                    syncStatusBanner.visibility = View.VISIBLE
+                }
+                SyncStateManager.SyncState.COMPLETED -> {
+                    // Re-enable sync controls
+                    setSyncControlsEnabled(true)
+                    swipeRefreshLayout.isRefreshing = false
+                    // Show completed briefly, then hide
+                    syncStatusText.text = status.message ?: getString(R.string.sync_status_completed)
+                    lifecycleScope.launch {
+                        kotlinx.coroutines.delay(SYNC_COMPLETED_DELAY_MS)
+                        syncStatusBanner.visibility = View.GONE
+                        SyncStateManager.reset()
+                    }
+                }
+                SyncStateManager.SyncState.ERROR -> {
+                    // Re-enable sync controls
+                    setSyncControlsEnabled(true)
+                    swipeRefreshLayout.isRefreshing = false
+                    // Show error briefly, then hide
+                    syncStatusText.text = status.message ?: getString(R.string.sync_status_error)
+                    lifecycleScope.launch {
+                        kotlinx.coroutines.delay(ERROR_DISPLAY_DELAY_MS)
+                        syncStatusBanner.visibility = View.GONE
+                        SyncStateManager.reset()
+                    }
+                }
+                SyncStateManager.SyncState.IDLE -> {
+                    setSyncControlsEnabled(true)
+                    swipeRefreshLayout.isRefreshing = false
+                    syncStatusBanner.visibility = View.GONE
+                }
+            }
+        }
+    }
+    
+    /**
+     * 🔄 v1.3.1: Aktiviert/deaktiviert Sync-Controls (Button + SwipeRefresh)
+     */
+    private fun setSyncControlsEnabled(enabled: Boolean) {
+        // Menu Sync-Button
+        optionsMenu?.findItem(R.id.action_sync)?.isEnabled = enabled
+        // SwipeRefresh
+        swipeRefreshLayout.isEnabled = enabled
     }
     
     override fun onResume() {
@@ -145,6 +223,12 @@ class MainActivity : AppCompatActivity() {
             return
         }
         
+        // 🔄 v1.3.1: Check if sync already running
+        if (!SyncStateManager.tryStartSync("auto-$source")) {
+            Logger.d(TAG, "⏭️ Auto-sync ($source): Another sync already in progress")
+            return
+        }
+        
         Logger.d(TAG, "🔄 Auto-sync triggered ($source)")
         
         // Update last sync timestamp
@@ -157,6 +241,7 @@ class MainActivity : AppCompatActivity() {
                 // 🔥 v1.1.2: Check if there are unsynced changes first (performance optimization)
                 if (!syncService.hasUnsyncedChanges()) {
                     Logger.d(TAG, "⏭️ Auto-sync ($source): No unsynced changes - skipping")
+                    SyncStateManager.reset()
                     return@launch
                 }
                 
@@ -167,6 +252,7 @@ class MainActivity : AppCompatActivity() {
                 
                 if (!isReachable) {
                     Logger.d(TAG, "⏭️ Auto-sync ($source): Server not reachable - skipping silently")
+                    SyncStateManager.reset()
                     return@launch
                 }
                 
@@ -178,6 +264,7 @@ class MainActivity : AppCompatActivity() {
                 // Feedback abhängig von Source
                 if (result.isSuccess && result.syncedCount > 0) {
                     Logger.d(TAG, "✅ Auto-sync successful ($source): ${result.syncedCount} notes")
+                    SyncStateManager.markCompleted("${result.syncedCount} Notizen")
                     
                     // onResume: Nur Success-Toast
                     showToast("✅ Gesynct: ${result.syncedCount} Notizen")
@@ -185,14 +272,17 @@ class MainActivity : AppCompatActivity() {
                     
                 } else if (result.isSuccess) {
                     Logger.d(TAG, "ℹ️ Auto-sync ($source): No changes")
+                    SyncStateManager.markCompleted()
                     
                 } else {
                     Logger.e(TAG, "❌ Auto-sync failed ($source): ${result.errorMessage}")
+                    SyncStateManager.markError(result.errorMessage)
                     // Kein Toast - App ist im Hintergrund
                 }
                 
             } catch (e: Exception) {
                 Logger.e(TAG, "💥 Auto-sync exception ($source): ${e.message}")
+                SyncStateManager.markError(e.message)
                 // Kein Toast - App ist im Hintergrund
             }
         }
@@ -229,6 +319,10 @@ class MainActivity : AppCompatActivity() {
         fabAddNote = findViewById(R.id.fabAddNote)
         toolbar = findViewById(R.id.toolbar)
         swipeRefreshLayout = findViewById<SwipeRefreshLayout>(R.id.swipeRefreshLayout)
+        
+        // 🔄 v1.3.1: Sync Status Banner
+        syncStatusBanner = findViewById(R.id.syncStatusBanner)
+        syncStatusText = findViewById(R.id.syncStatusText)
     }
     
     private fun setupToolbar() {
@@ -256,6 +350,12 @@ class MainActivity : AppCompatActivity() {
         swipeRefreshLayout.setOnRefreshListener {
             Logger.d(TAG, "🔄 Pull-to-Refresh triggered - starting manual sync")
             
+            // 🔄 v1.3.1: Check if sync already running (Banner zeigt Status)
+            if (!SyncStateManager.tryStartSync("pullToRefresh")) {
+                swipeRefreshLayout.isRefreshing = false
+                return@setOnRefreshListener
+            }
+            
             lifecycleScope.launch {
                 try {
                     val prefs = getSharedPreferences(Constants.PREFS_NAME, Context.MODE_PRIVATE)
@@ -263,7 +363,7 @@ class MainActivity : AppCompatActivity() {
                     
                     if (serverUrl.isNullOrEmpty()) {
                         showToast("⚠️ Server noch nicht konfiguriert")
-                        swipeRefreshLayout.isRefreshing = false
+                        SyncStateManager.reset()
                         return@launch
                     }
                     
@@ -272,15 +372,13 @@ class MainActivity : AppCompatActivity() {
                     // 🔥 v1.1.2: Check if there are unsynced changes first (performance optimization)
                     if (!syncService.hasUnsyncedChanges()) {
                         Logger.d(TAG, "⏭️ No unsynced changes, skipping server reachability check")
-                        showToast("✅ Bereits synchronisiert")
-                        swipeRefreshLayout.isRefreshing = false
+                        SyncStateManager.markCompleted("Bereits synchronisiert")
                         return@launch
                     }
                     
                     // Check if server is reachable
                     if (!syncService.isServerReachable()) {
-                        showToast("⚠️ Server nicht erreichbar")
-                        swipeRefreshLayout.isRefreshing = false
+                        SyncStateManager.markError("Server nicht erreichbar")
                         return@launch
                     }
                     
@@ -288,16 +386,14 @@ class MainActivity : AppCompatActivity() {
                     val result = syncService.syncNotes()
                     
                     if (result.isSuccess) {
-                        showToast("✅ ${result.syncedCount} Notizen synchronisiert")
+                        SyncStateManager.markCompleted("${result.syncedCount} Notizen")
                         loadNotes()
                     } else {
-                        showToast("❌ Sync fehlgeschlagen: ${result.errorMessage}")
+                        SyncStateManager.markError(result.errorMessage)
                     }
                 } catch (e: Exception) {
                     Logger.e(TAG, "Pull-to-Refresh sync failed", e)
-                    showToast("❌ Fehler: ${e.message}")
-                } finally {
-                    swipeRefreshLayout.isRefreshing = false
+                    SyncStateManager.markError(e.message)
                 }
             }
         }
@@ -320,36 +416,20 @@ class MainActivity : AppCompatActivity() {
             ): Boolean = false
             
             override fun onSwiped(viewHolder: RecyclerView.ViewHolder, direction: Int) {
-                val position = viewHolder.adapterPosition
-                val note = adapter.currentList[position]
-                val notesCopy = adapter.currentList.toMutableList()
+                val position = viewHolder.bindingAdapterPosition
+                val swipedNote = adapter.currentList[position]
                 
-                // Track pending deletion to prevent flicker
-                pendingDeletions.add(note.id)
+                // Store original list BEFORE removing note
+                val originalList = adapter.currentList.toList()
                 
-                // Remove from list immediately for visual feedback
-                notesCopy.removeAt(position)
-                adapter.submitList(notesCopy)
-                
-                // Show Snackbar with UNDO
-                Snackbar.make(
-                    recyclerViewNotes,
-                    "Notiz gelöscht",
-                    Snackbar.LENGTH_LONG
-                ).setAction("RÜCKGÄNGIG") {
-                    // UNDO: Remove from pending deletions and restore
-                    pendingDeletions.remove(note.id)
-                    loadNotes()
-                }.addCallback(object : Snackbar.Callback() {
-                    override fun onDismissed(transientBottomBar: Snackbar?, event: Int) {
-                        if (event != DISMISS_EVENT_ACTION) {
-                            // Snackbar dismissed without UNDO → Actually delete the note
-                            storage.deleteNote(note.id)
-                            pendingDeletions.remove(note.id)
-                            loadNotes()
+                // Remove from list for visual feedback (NOT from storage yet!)
+                val listWithoutNote = originalList.toMutableList().apply {
+                    removeAt(position)
                 }
-                    }
-                }).show()
+                adapter.submitList(listWithoutNote)
+                
+                // Show dialog with ability to restore
+                showServerDeletionDialog(swipedNote, originalList)
             }
             
             override fun getSwipeThreshold(viewHolder: RecyclerView.ViewHolder): Float {
@@ -361,6 +441,116 @@ class MainActivity : AppCompatActivity() {
         itemTouchHelper.attachToRecyclerView(recyclerViewNotes)
     }
     
+    private fun showServerDeletionDialog(note: Note, originalList: List<Note>) {
+        val alwaysDeleteFromServer = prefs.getBoolean(Constants.KEY_ALWAYS_DELETE_FROM_SERVER, false)
+        
+        if (alwaysDeleteFromServer) {
+            // Auto-delete from server without asking
+            deleteNoteLocally(note, deleteFromServer = true)
+            return
+        }
+        
+        val dialogView = layoutInflater.inflate(R.layout.dialog_server_deletion, null)
+        val checkboxAlways = dialogView.findViewById<CheckBox>(R.id.checkboxAlwaysDeleteFromServer)
+        
+        MaterialAlertDialogBuilder(this)
+            .setTitle("Notiz löschen")
+            .setMessage("\"${note.title}\" wird lokal gelöscht.\n\nAuch vom Server löschen?")
+            .setView(dialogView)
+            .setNeutralButton("Abbrechen") { _, _ ->
+                // RESTORE: Re-submit original list (note is NOT deleted from storage)
+                adapter.submitList(originalList)
+            }
+            .setOnCancelListener {
+                // User pressed back - also restore
+                adapter.submitList(originalList)
+            }
+            .setPositiveButton("Nur lokal") { _, _ ->
+                if (checkboxAlways.isChecked) {
+                    prefs.edit().putBoolean(Constants.KEY_ALWAYS_DELETE_FROM_SERVER, false).apply()
+                }
+                // NOW actually delete from storage
+                deleteNoteLocally(note, deleteFromServer = false)
+            }
+            .setNegativeButton("Vom Server löschen") { _, _ ->
+                if (checkboxAlways.isChecked) {
+                    prefs.edit().putBoolean(Constants.KEY_ALWAYS_DELETE_FROM_SERVER, true).apply()
+                }
+                deleteNoteLocally(note, deleteFromServer = true)
+            }
+            .setCancelable(true)
+            .show()
+    }
+    
+    private fun deleteNoteLocally(note: Note, deleteFromServer: Boolean) {
+        // Track pending deletion to prevent flicker
+        pendingDeletions.add(note.id)
+        
+        // Delete from storage
+        storage.deleteNote(note.id)
+        
+        // Reload to reflect changes
+        loadNotes()
+        
+        // Show Snackbar with UNDO option
+        val message = if (deleteFromServer) {
+            "\"${note.title}\" wird lokal und vom Server gelöscht"
+        } else {
+            "\"${note.title}\" lokal gelöscht (Server bleibt)"
+        }
+        
+        Snackbar.make(recyclerViewNotes, message, Snackbar.LENGTH_LONG)
+            .setAction("RÜCKGÄNGIG") {
+                // UNDO: Restore note
+                storage.saveNote(note)
+                pendingDeletions.remove(note.id)
+                loadNotes()
+            }
+            .addCallback(object : Snackbar.Callback() {
+                override fun onDismissed(transientBottomBar: Snackbar?, event: Int) {
+                    if (event != DISMISS_EVENT_ACTION) {
+                        // Snackbar dismissed without UNDO
+                        pendingDeletions.remove(note.id)
+                        
+                        // Delete from server if requested
+                        if (deleteFromServer) {
+                            lifecycleScope.launch {
+                                try {
+                                    val webdavService = WebDavSyncService(this@MainActivity)
+                                    val success = webdavService.deleteNoteFromServer(note.id)
+                                    if (success) {
+                                        runOnUiThread {
+                                            Toast.makeText(
+                                                this@MainActivity,
+                                                "Vom Server gelöscht",
+                                                Toast.LENGTH_SHORT
+                                            ).show()
+                                        }
+                                    } else {
+                                        runOnUiThread {
+                                            Toast.makeText(
+                                                this@MainActivity,
+                                                "Server-Löschung fehlgeschlagen",
+                                                Toast.LENGTH_LONG
+                                            ).show()
+                                        }
+                                    }
+                                } catch (e: Exception) {
+                                    runOnUiThread {
+                                        Toast.makeText(
+                                            this@MainActivity,
+                                            "Server-Fehler: ${e.message}",
+                                            Toast.LENGTH_LONG
+                                        ).show()
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }).show()
+    }
+    
     private fun setupFab() {
         fabAddNote.setOnClickListener {
             openNoteEditor(null)
@@ -405,6 +595,11 @@ class MainActivity : AppCompatActivity() {
     }
     
     private fun triggerManualSync() {
+        // 🔄 v1.3.1: Check if sync already running (Banner zeigt Status)
+        if (!SyncStateManager.tryStartSync("manual")) {
+            return
+        }
+        
         lifecycleScope.launch {
             try {
                 // Create sync service
@@ -413,12 +608,10 @@ class MainActivity : AppCompatActivity() {
                 // 🔥 v1.1.2: Check if there are unsynced changes first (performance optimization)
                 if (!syncService.hasUnsyncedChanges()) {
                     Logger.d(TAG, "⏭️ Manual Sync: No unsynced changes - skipping")
-                    showToast("✅ Bereits synchronisiert")
+                    SyncStateManager.markCompleted("Bereits synchronisiert")
                     return@launch
                 }
                 
-                showToast("Starte Synchronisation...")
-                
                 // ⭐ WICHTIG: Server-Erreichbarkeits-Check VOR Sync (wie in SyncWorker)
                 val isReachable = withContext(Dispatchers.IO) {
                     syncService.isServerReachable()
@@ -426,7 +619,7 @@ class MainActivity : AppCompatActivity() {
                 
                 if (!isReachable) {
                     Logger.d(TAG, "⏭️ Manual Sync: Server not reachable - aborting")
-                    showToast("Server nicht erreichbar")
+                    SyncStateManager.markError("Server nicht erreichbar")
                     return@launch
                 }
                 
@@ -437,20 +630,21 @@ class MainActivity : AppCompatActivity() {
                 
                 // Show result
                 if (result.isSuccess) {
-                    showToast("Sync erfolgreich: ${result.syncedCount} Notizen")
+                    SyncStateManager.markCompleted("${result.syncedCount} Notizen")
                     loadNotes() // Reload notes
                 } else {
-                    showToast("Sync Fehler: ${result.errorMessage}")
+                    SyncStateManager.markError(result.errorMessage)
                 }
                 
             } catch (e: Exception) {
-                showToast("Sync Fehler: ${e.message}")
+                SyncStateManager.markError(e.message)
             }
         }
     }
     
     override fun onCreateOptionsMenu(menu: Menu): Boolean {
         menuInflater.inflate(R.menu.menu_main, menu)
+        optionsMenu = menu  // 🔄 v1.3.1: Store reference for sync button state
         return true
     }
     

android/app/src/main/java/dev/dettmer/simplenotes/SettingsActivity.kt

@@ -1,5 +1,6 @@
 package dev.dettmer.simplenotes
 
+import android.app.ProgressDialog
 import android.content.Context
 import android.content.Intent
 import android.net.Uri
@@ -8,11 +9,13 @@ import android.os.PowerManager
 import android.provider.Settings
 import android.util.Log
 import android.view.MenuItem
+import android.view.View
 import android.widget.Button
 import android.widget.EditText
 import android.widget.RadioButton
 import android.widget.RadioGroup
 import android.widget.TextView
+import androidx.activity.result.contract.ActivityResultContracts
 import androidx.appcompat.app.AlertDialog
 import androidx.appcompat.app.AppCompatActivity
 import androidx.appcompat.widget.SwitchCompat
@@ -22,18 +25,18 @@ import androidx.localbroadcastmanager.content.LocalBroadcastManager
 import com.google.android.material.appbar.MaterialToolbar
 import com.google.android.material.card.MaterialCardView
 import com.google.android.material.color.DynamicColors
-import com.google.android.material.switchmaterial.SwitchMaterial
-import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
+import dev.dettmer.simplenotes.backup.BackupManager
+import dev.dettmer.simplenotes.backup.RestoreMode
 import dev.dettmer.simplenotes.utils.UrlValidator
 import kotlinx.coroutines.withContext
 import dev.dettmer.simplenotes.sync.WebDavSyncService
+import dev.dettmer.simplenotes.sync.SyncStateManager
 import dev.dettmer.simplenotes.sync.NetworkMonitor
 import dev.dettmer.simplenotes.utils.Constants
 import dev.dettmer.simplenotes.utils.Logger
 import dev.dettmer.simplenotes.utils.showToast
-import java.io.File
 import java.net.HttpURLConnection
 import java.net.URL
 import java.text.SimpleDateFormat
@@ -46,6 +49,7 @@ class SettingsActivity : AppCompatActivity() {
         private const val GITHUB_REPO_URL = "https://github.com/inventory69/simple-notes-sync"
         private const val GITHUB_PROFILE_URL = "https://github.com/inventory69"
         private const val LICENSE_URL = "https://github.com/inventory69/simple-notes-sync/blob/main/LICENSE"
+        private const val CONNECTION_TIMEOUT_MS = 3000
     }
     
     private lateinit var textInputLayoutServerUrl: com.google.android.material.textfield.TextInputLayout
@@ -53,10 +57,15 @@ class SettingsActivity : AppCompatActivity() {
     private lateinit var editTextUsername: EditText
     private lateinit var editTextPassword: EditText
     private lateinit var switchAutoSync: SwitchCompat
+    private lateinit var switchMarkdownAutoSync: SwitchCompat
     private lateinit var buttonTestConnection: Button
     private lateinit var buttonSyncNow: Button
+    private lateinit var buttonCreateBackup: Button
+    private lateinit var buttonRestoreFromFile: Button
     private lateinit var buttonRestoreFromServer: Button
+    private lateinit var buttonManualMarkdownSync: Button
     private lateinit var textViewServerStatus: TextView
+    private lateinit var textViewManualSyncInfo: TextView
     
     // Protocol Selection UI
     private lateinit var protocolRadioGroup: RadioGroup
@@ -73,6 +82,27 @@ class SettingsActivity : AppCompatActivity() {
     private lateinit var cardDeveloperProfile: MaterialCardView
     private lateinit var cardLicense: MaterialCardView
     
+    // Debug Section UI
+    private lateinit var switchFileLogging: com.google.android.material.materialswitch.MaterialSwitch
+    private lateinit var buttonExportLogs: Button
+    private lateinit var buttonClearLogs: Button
+    
+    // Backup Manager
+    private val backupManager by lazy { BackupManager(this) }
+    
+    // Activity Result Launchers
+    private val createBackupLauncher = registerForActivityResult(
+        ActivityResultContracts.CreateDocument("application/json")
+    ) { uri ->
+        uri?.let { createBackup(it) }
+    }
+    
+    private val restoreBackupLauncher = registerForActivityResult(
+        ActivityResultContracts.OpenDocument()
+    ) { uri ->
+        uri?.let { showRestoreDialog(RestoreSource.LOCAL_FILE, it) }
+    }
+    
     private val prefs by lazy {
         getSharedPreferences(Constants.PREFS_NAME, MODE_PRIVATE)
     }
@@ -98,6 +128,7 @@ class SettingsActivity : AppCompatActivity() {
         setupListeners()
         setupSyncIntervalPicker()
         setupAboutSection()
+        setupDebugSection()
     }
     
     private fun findViews() {
@@ -106,10 +137,15 @@ class SettingsActivity : AppCompatActivity() {
         editTextUsername = findViewById(R.id.editTextUsername)
         editTextPassword = findViewById(R.id.editTextPassword)
         switchAutoSync = findViewById(R.id.switchAutoSync)
+        switchMarkdownAutoSync = findViewById(R.id.switchMarkdownAutoSync)
         buttonTestConnection = findViewById(R.id.buttonTestConnection)
         buttonSyncNow = findViewById(R.id.buttonSyncNow)
+        buttonCreateBackup = findViewById(R.id.buttonCreateBackup)
+        buttonRestoreFromFile = findViewById(R.id.buttonRestoreFromFile)
         buttonRestoreFromServer = findViewById(R.id.buttonRestoreFromServer)
+        buttonManualMarkdownSync = findViewById(R.id.buttonManualMarkdownSync)
         textViewServerStatus = findViewById(R.id.textViewServerStatus)
+        textViewManualSyncInfo = findViewById(R.id.textViewManualSyncInfo)
         
         // Protocol Selection UI
         protocolRadioGroup = findViewById(R.id.protocolRadioGroup)
@@ -125,6 +161,11 @@ class SettingsActivity : AppCompatActivity() {
         cardGitHubRepo = findViewById(R.id.cardGitHubRepo)
         cardDeveloperProfile = findViewById(R.id.cardDeveloperProfile)
         cardLicense = findViewById(R.id.cardLicense)
+        
+        // Debug Section UI
+        switchFileLogging = findViewById(R.id.switchFileLogging)
+        buttonExportLogs = findViewById(R.id.buttonExportLogs)
+        buttonClearLogs = findViewById(R.id.buttonClearLogs)
     }
     
     private fun loadSettings() {
@@ -153,6 +194,14 @@ class SettingsActivity : AppCompatActivity() {
         editTextPassword.setText(prefs.getString(Constants.KEY_PASSWORD, ""))
         switchAutoSync.isChecked = prefs.getBoolean(Constants.KEY_AUTO_SYNC, false)
         
+        // Load Markdown Auto-Sync (backward compatible)
+        val markdownExport = prefs.getBoolean(Constants.KEY_MARKDOWN_EXPORT, false)
+        val markdownAutoImport = prefs.getBoolean(Constants.KEY_MARKDOWN_AUTO_IMPORT, false)
+        val markdownAutoSync = markdownExport && markdownAutoImport
+        switchMarkdownAutoSync.isChecked = markdownAutoSync
+        
+        updateMarkdownButtonVisibility()
+        
         // Update hint text based on selected protocol
         updateProtocolHint()
         
@@ -223,15 +272,35 @@ class SettingsActivity : AppCompatActivity() {
             syncNow()
         }
         
+        buttonCreateBackup.setOnClickListener {
+            // Dateiname mit Timestamp
+            val timestamp = SimpleDateFormat("yyyy-MM-dd_HHmmss", Locale.US)
+                .format(java.util.Date())
+            val filename = "simplenotes_backup_$timestamp.json"
+            createBackupLauncher.launch(filename)
+        }
+        
+        buttonRestoreFromFile.setOnClickListener {
+            restoreBackupLauncher.launch(arrayOf("application/json"))
+        }
+        
         buttonRestoreFromServer.setOnClickListener {
             saveSettings()
-            showRestoreConfirmation()
+            showRestoreDialog(RestoreSource.WEBDAV_SERVER, null)
+        }
+        
+        buttonManualMarkdownSync.setOnClickListener {
+            performManualMarkdownSync()
         }
         
         switchAutoSync.setOnCheckedChangeListener { _, isChecked ->
             onAutoSyncToggled(isChecked)
         }
         
+        switchMarkdownAutoSync.setOnCheckedChangeListener { _, isChecked ->
+            onMarkdownAutoSyncToggled(isChecked)
+        }
+        
         // Clear error when user starts typing again
         editTextServerUrl.addTextChangedListener(object : android.text.TextWatcher {
             override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {}
@@ -254,7 +323,10 @@ class SettingsActivity : AppCompatActivity() {
      */
     private fun setupSyncIntervalPicker() {
         // Load current interval from preferences
-        val currentInterval = prefs.getLong(Constants.PREF_SYNC_INTERVAL_MINUTES, Constants.DEFAULT_SYNC_INTERVAL_MINUTES)
+        val currentInterval = prefs.getLong(
+            Constants.PREF_SYNC_INTERVAL_MINUTES,
+            Constants.DEFAULT_SYNC_INTERVAL_MINUTES
+        )
         
         // Set checked radio button based on current interval
         val checkedId = when (currentInterval) {
@@ -327,6 +399,109 @@ class SettingsActivity : AppCompatActivity() {
         }
     }
     
+    /**
+     * Setup Debug section with file logging toggle and export functionality
+     */
+    private fun setupDebugSection() {
+        // Load current file logging state
+        val fileLoggingEnabled = prefs.getBoolean(Constants.KEY_FILE_LOGGING_ENABLED, false)
+        switchFileLogging.isChecked = fileLoggingEnabled
+        
+        // Update Logger state
+        Logger.setFileLoggingEnabled(fileLoggingEnabled)
+        
+        // Toggle file logging
+        switchFileLogging.setOnCheckedChangeListener { _, isChecked ->
+            prefs.edit().putBoolean(Constants.KEY_FILE_LOGGING_ENABLED, isChecked).apply()
+            Logger.setFileLoggingEnabled(isChecked)
+            
+            if (isChecked) {
+                showToast("📝 Datei-Logging aktiviert")
+                Logger.i(TAG, "File logging enabled by user")
+            } else {
+                showToast("📝 Datei-Logging deaktiviert")
+            }
+        }
+        
+        // Export logs button
+        buttonExportLogs.setOnClickListener {
+            exportAndShareLogs()
+        }
+        
+        // Clear logs button
+        buttonClearLogs.setOnClickListener {
+            showClearLogsConfirmation()
+        }
+    }
+    
+    /**
+     * Export logs and share via system share sheet
+     */
+    private fun exportAndShareLogs() {
+        lifecycleScope.launch {
+            try {
+                val logFile = Logger.getLogFile(this@SettingsActivity)
+                
+                if (logFile == null || !logFile.exists() || logFile.length() == 0L) {
+                    showToast("📭 Keine Logs vorhanden")
+                    return@launch
+                }
+                
+                // Create share intent using FileProvider
+                val logUri = FileProvider.getUriForFile(
+                    this@SettingsActivity,
+                    "${BuildConfig.APPLICATION_ID}.fileprovider",
+                    logFile
+                )
+                
+                val shareIntent = Intent(Intent.ACTION_SEND).apply {
+                    type = "text/plain"
+                    putExtra(Intent.EXTRA_STREAM, logUri)
+                    putExtra(Intent.EXTRA_SUBJECT, "SimpleNotes Sync Logs")
+                    addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
+                }
+                
+                startActivity(Intent.createChooser(shareIntent, "Logs teilen via..."))
+                Logger.i(TAG, "Logs exported and shared")
+                
+            } catch (e: Exception) {
+                Logger.e(TAG, "Failed to export logs", e)
+                showToast("❌ Fehler beim Exportieren: ${e.message}")
+            }
+        }
+    }
+    
+    /**
+     * Show confirmation dialog before clearing logs
+     */
+    private fun showClearLogsConfirmation() {
+        AlertDialog.Builder(this)
+            .setTitle("Logs löschen?")
+            .setMessage("Alle gespeicherten Sync-Logs werden unwiderruflich gelöscht.")
+            .setPositiveButton("Löschen") { _, _ ->
+                clearLogs()
+            }
+            .setNegativeButton("Abbrechen", null)
+            .show()
+    }
+    
+    /**
+     * Clear all log files
+     */
+    private fun clearLogs() {
+        try {
+            val cleared = Logger.clearLogFile(this)
+            if (cleared) {
+                showToast("🗑️ Logs gelöscht")
+            } else {
+                showToast("📭 Keine Logs zum Löschen")
+            }
+        } catch (e: Exception) {
+            Logger.e(TAG, "Failed to clear logs", e)
+            showToast("❌ Fehler beim Löschen: ${e.message}")
+        }
+    }
+    
     /**
      * Opens URL in browser
      */
@@ -408,6 +583,14 @@ class SettingsActivity : AppCompatActivity() {
     }
     
     private fun syncNow() {
+        // 🔄 v1.3.1: Check if sync already running (Button wird deaktiviert)
+        if (!SyncStateManager.tryStartSync("settings")) {
+            return
+        }
+        
+        // Disable button during sync
+        buttonSyncNow.isEnabled = false
+        
         lifecycleScope.launch {
             try {
                 val syncService = WebDavSyncService(this@SettingsActivity)
@@ -415,14 +598,16 @@ class SettingsActivity : AppCompatActivity() {
                 // 🔥 v1.1.2: Check if there are unsynced changes first (performance optimization)
                 if (!syncService.hasUnsyncedChanges()) {
                     showToast("✅ Bereits synchronisiert")
+                    SyncStateManager.markCompleted()
                     return@launch
                 }
                 
-                showToast("Synchronisiere...")
+                showToast("🔄 Synchronisiere...")
                 
                 // ⭐ WICHTIG: Server-Erreichbarkeits-Check VOR Sync (wie in anderen Triggern)
                 if (!syncService.isServerReachable()) {
                     showToast("⚠️ Server nicht erreichbar")
+                    SyncStateManager.markError("Server nicht erreichbar")
                     checkServerStatus() // Server-Status aktualisieren
                     return@launch
                 }
@@ -431,18 +616,24 @@ class SettingsActivity : AppCompatActivity() {
                 
                 if (result.isSuccess) {
                     if (result.hasConflicts) {
-                        showToast("Sync abgeschlossen. ${result.conflictCount} Konflikte erkannt!")
+                        showToast("✅ Sync abgeschlossen. ${result.conflictCount} Konflikte erkannt!")
                     } else {
-                        showToast("Erfolgreich! ${result.syncedCount} Notizen synchronisiert")
+                        showToast("✅ Erfolgreich! ${result.syncedCount} Notizen synchronisiert")
                     }
+                    SyncStateManager.markCompleted("${result.syncedCount} Notizen")
                     checkServerStatus() // ✅ Server-Status nach Sync aktualisieren
                 } else {
-                    showToast("Sync fehlgeschlagen: ${result.errorMessage}")
+                    showToast("❌ Sync fehlgeschlagen: ${result.errorMessage}")
+                    SyncStateManager.markError(result.errorMessage)
                     checkServerStatus() // ✅ Auch bei Fehler aktualisieren
                 }
             } catch (e: Exception) {
-                showToast("Fehler: ${e.message}")
+                showToast("❌ Fehler: ${e.message}")
+                SyncStateManager.markError(e.message)
                 checkServerStatus() // ✅ Auch bei Exception aktualisieren
+            } finally {
+                // Re-enable button
+                buttonSyncNow.isEnabled = true
             }
         }
     }
@@ -464,8 +655,8 @@ class SettingsActivity : AppCompatActivity() {
                 try {
                     val url = URL(serverUrl)
                     val connection = url.openConnection() as HttpURLConnection
-                    connection.connectTimeout = 3000
-                    connection.readTimeout = 3000
+                    connection.connectTimeout = CONNECTION_TIMEOUT_MS
+                    connection.readTimeout = CONNECTION_TIMEOUT_MS
                     val code = connection.responseCode
                     connection.disconnect()
                     code in 200..299 || code == 401  // 401 = Server da, Auth fehlt
@@ -498,6 +689,106 @@ class SettingsActivity : AppCompatActivity() {
         }
     }
     
+    private fun onMarkdownAutoSyncToggled(enabled: Boolean) {
+        if (enabled) {
+            // Initial-Export wenn Feature aktiviert wird
+            lifecycleScope.launch {
+                try {
+                    val noteStorage = dev.dettmer.simplenotes.storage.NotesStorage(this@SettingsActivity)
+                    val currentNoteCount = noteStorage.loadAllNotes().size
+                    
+                    if (currentNoteCount > 0) {
+                        // Zeige Progress-Dialog
+                        val progressDialog = ProgressDialog(this@SettingsActivity).apply {
+                            setTitle("Markdown Auto-Sync")
+                            setMessage("Exportiere Notizen nach Markdown...")
+                            setProgressStyle(ProgressDialog.STYLE_HORIZONTAL)
+                            max = currentNoteCount
+                            progress = 0
+                            setCancelable(false)
+                            show()
+                        }
+                        
+                        try {
+                            // Hole Server-Daten
+                            val serverUrl = prefs.getString(Constants.KEY_SERVER_URL, "") ?: ""
+                            val username = prefs.getString(Constants.KEY_USERNAME, "") ?: ""
+                            val password = prefs.getString(Constants.KEY_PASSWORD, "") ?: ""
+                            
+                            if (serverUrl.isBlank() || username.isBlank() || password.isBlank()) {
+                                progressDialog.dismiss()
+                                showToast("⚠️ Bitte zuerst WebDAV-Server konfigurieren")
+                                switchMarkdownAutoSync.isChecked = false
+                                return@launch
+                            }
+                            
+                            // Führe Initial-Export aus
+                            val syncService = WebDavSyncService(this@SettingsActivity)
+                            val exportedCount = syncService.exportAllNotesToMarkdown(
+                                serverUrl = serverUrl,
+                                username = username,
+                                password = password,
+                                onProgress = { current, total ->
+                                    runOnUiThread {
+                                        progressDialog.progress = current
+                                        progressDialog.setMessage("Exportiere $current/$total Notizen...")
+                                    }
+                                }
+                            )
+                            
+                            progressDialog.dismiss()
+                            
+                            // Speichere beide Einstellungen
+                            prefs.edit()
+                                .putBoolean(Constants.KEY_MARKDOWN_EXPORT, enabled)
+                                .putBoolean(Constants.KEY_MARKDOWN_AUTO_IMPORT, enabled)
+                                .apply()
+                            
+                            updateMarkdownButtonVisibility()
+                            
+                            // Erfolgs-Nachricht
+                            showToast("✅ $exportedCount Notizen nach Markdown exportiert")
+                            
+                        } catch (e: Exception) {
+                            progressDialog.dismiss()
+                            showToast("❌ Export fehlgeschlagen: ${e.message}")
+                            
+                            // Deaktiviere Toggle bei Fehler
+                            switchMarkdownAutoSync.isChecked = false
+                            return@launch
+                        }
+                    } else {
+                        // Keine Notizen vorhanden - speichere Einstellungen direkt
+                        prefs.edit()
+                            .putBoolean(Constants.KEY_MARKDOWN_EXPORT, enabled)
+                            .putBoolean(Constants.KEY_MARKDOWN_AUTO_IMPORT, enabled)
+                            .apply()
+                        
+                        updateMarkdownButtonVisibility()
+                        showToast(
+                            "Markdown Auto-Sync aktiviert - " +
+                                "Notizen werden als .md-Dateien exportiert und importiert"
+                        )
+                    }
+                    
+                } catch (e: Exception) {
+                    Logger.e(TAG, "Error toggling markdown auto-sync: ${e.message}")
+                    showToast("Fehler: ${e.message}")
+                    switchMarkdownAutoSync.isChecked = false
+                }
+            }
+        } else {
+            // Deaktivieren - Settings speichern
+            prefs.edit()
+                .putBoolean(Constants.KEY_MARKDOWN_EXPORT, enabled)
+                .putBoolean(Constants.KEY_MARKDOWN_AUTO_IMPORT, enabled)
+                .apply()
+            
+            updateMarkdownButtonVisibility()
+            showToast("Markdown Auto-Sync deaktiviert - nur JSON-Sync aktiv")
+        }
+    }
+    
     private fun checkBatteryOptimization() {
         val powerManager = getSystemService(Context.POWER_SERVICE) as PowerManager
         val packageName = packageName
@@ -531,11 +822,13 @@ class SettingsActivity : AppCompatActivity() {
             intent.data = Uri.parse("package:$packageName")
             startActivity(intent)
         } catch (e: Exception) {
+            Logger.w(TAG, "Failed to open battery optimization settings: ${e.message}")
             // Fallback: Open general battery settings
             try {
                 val intent = Intent(Settings.ACTION_IGNORE_BATTERY_OPTIMIZATION_SETTINGS)
                 startActivity(intent)
             } catch (e2: Exception) {
+                Logger.w(TAG, "Failed to open fallback battery settings: ${e2.message}")
                 showToast("Bitte Akku-Optimierung manuell deaktivieren")
             }
         }
@@ -554,49 +847,6 @@ class SettingsActivity : AppCompatActivity() {
         }
     }
     
-    private fun showRestoreConfirmation() {
-        android.app.AlertDialog.Builder(this)
-            .setTitle(R.string.restore_confirmation_title)
-            .setMessage(R.string.restore_confirmation_message)
-            .setPositiveButton(R.string.restore_button) { _, _ ->
-                performRestore()
-            }
-            .setNegativeButton(R.string.cancel, null)
-            .show()
-    }
-    
-    private fun performRestore() {
-        val progressDialog = android.app.ProgressDialog(this).apply {
-            setMessage(getString(R.string.restore_progress))
-            setCancelable(false)
-            show()
-        }
-        
-        CoroutineScope(Dispatchers.Main).launch {
-            try {
-                val webdavService = WebDavSyncService(this@SettingsActivity)
-                val result = withContext(Dispatchers.IO) {
-                    webdavService.restoreFromServer()
-                }
-                
-                progressDialog.dismiss()
-                
-                if (result.isSuccess) {
-                    showToast(getString(R.string.restore_success, result.restoredCount))
-                    // Refresh MainActivity's note list
-                    setResult(RESULT_OK)
-                } else {
-                    showToast(getString(R.string.restore_error, result.errorMessage))
-                }
-                checkServerStatus()
-            } catch (e: Exception) {
-                progressDialog.dismiss()
-                showToast(getString(R.string.restore_error, e.message))
-                checkServerStatus()
-            }
-        }
-    }
-    
     override fun onOptionsItemSelected(item: MenuItem): Boolean {
         return when (item.itemId) {
             android.R.id.home -> {
@@ -612,4 +862,286 @@ class SettingsActivity : AppCompatActivity() {
         super.onPause()
         saveSettings()
     }
+    
+    // ========================================
+    // BACKUP & RESTORE FUNCTIONS (v1.2.0)
+    // ========================================
+    
+    /**
+     * Restore-Quelle (Lokale Datei oder WebDAV Server)
+     */
+    private enum class RestoreSource {
+        LOCAL_FILE,
+        WEBDAV_SERVER
+    }
+    
+    /**
+     * Erstellt Backup (Task #1.2.0-04)
+     */
+    private fun createBackup(uri: Uri) {
+        lifecycleScope.launch {
+            try {
+                Logger.d(TAG, "📦 Creating backup...")
+                val result = backupManager.createBackup(uri)
+                
+                if (result.success) {
+                    showToast("✅ ${result.message}")
+                } else {
+                    showErrorDialog("Backup fehlgeschlagen", result.error ?: "Unbekannter Fehler")
+                }
+            } catch (e: Exception) {
+                Logger.e(TAG, "Failed to create backup", e)
+                showErrorDialog("Backup fehlgeschlagen", e.message ?: "Unbekannter Fehler")
+            }
+        }
+    }
+    
+    /**
+     * Universeller Restore-Dialog für beide Quellen (Task #1.2.0-05 + #1.2.0-05b)
+     * 
+     * @param source Lokale Datei oder WebDAV Server
+     * @param fileUri URI der lokalen Datei (nur für LOCAL_FILE)
+     */
+    private fun showRestoreDialog(source: RestoreSource, fileUri: Uri?) {
+        val sourceText = when (source) {
+            RestoreSource.LOCAL_FILE -> "Lokale Datei"
+            RestoreSource.WEBDAV_SERVER -> "WebDAV Server"
+        }
+        
+        // Custom View mit Radio Buttons
+        val radioGroup = android.widget.RadioGroup(this).apply {
+            orientation = android.widget.RadioGroup.VERTICAL
+            setPadding(50, 20, 50, 20)
+        }
+        
+        // Radio Buttons erstellen
+        val radioMerge = android.widget.RadioButton(this).apply {
+            text = "⚪ Zusammenführen (Standard)\n   → Neue hinzufügen, Bestehende behalten"
+            id = android.view.View.generateViewId()
+            isChecked = true
+            setPadding(10, 10, 10, 10)
+        }
+        
+        val radioReplace = android.widget.RadioButton(this).apply {
+            text = "⚪ Ersetzen\n   → Alle löschen & Backup importieren"
+            id = android.view.View.generateViewId()
+            setPadding(10, 10, 10, 10)
+        }
+        
+        val radioOverwrite = android.widget.RadioButton(this).apply {
+            text = "⚪ Duplikate überschreiben\n   → Backup gewinnt bei Konflikten"
+            id = android.view.View.generateViewId()
+            setPadding(10, 10, 10, 10)
+        }
+        
+        radioGroup.addView(radioMerge)
+        radioGroup.addView(radioReplace)
+        radioGroup.addView(radioOverwrite)
+        
+        // Hauptlayout
+        val mainLayout = android.widget.LinearLayout(this).apply {
+            orientation = android.widget.LinearLayout.VERTICAL
+            setPadding(50, 30, 50, 30)
+        }
+        
+        // Info Text
+        val infoText = android.widget.TextView(this).apply {
+            text = "Quelle: $sourceText\n\nWiederherstellungs-Modus:"
+            textSize = 16f
+            setPadding(0, 0, 0, 20)
+        }
+        
+        // Hinweis Text
+        val hintText = android.widget.TextView(this).apply {
+            text = "\nℹ️ Ein Sicherheits-Backup wird vor dem Wiederherstellen automatisch erstellt."
+            textSize = 14f
+            setTypeface(null, android.graphics.Typeface.ITALIC)
+            setPadding(0, 20, 0, 0)
+        }
+        
+        mainLayout.addView(infoText)
+        mainLayout.addView(radioGroup)
+        mainLayout.addView(hintText)
+        
+        // Dialog erstellen
+        AlertDialog.Builder(this)
+            .setTitle("⚠️ Backup wiederherstellen?")
+            .setView(mainLayout)
+            .setPositiveButton("Wiederherstellen") { _, _ ->
+                val selectedMode = when (radioGroup.checkedRadioButtonId) {
+                    radioReplace.id -> RestoreMode.REPLACE
+                    radioOverwrite.id -> RestoreMode.OVERWRITE_DUPLICATES
+                    else -> RestoreMode.MERGE
+                }
+                
+                when (source) {
+                    RestoreSource.LOCAL_FILE -> fileUri?.let { performRestoreFromFile(it, selectedMode) }
+                    RestoreSource.WEBDAV_SERVER -> performRestoreFromServer(selectedMode)
+                }
+            }
+            .setNegativeButton("Abbrechen", null)
+            .show()
+    }
+    
+    /**
+     * Führt Restore aus lokaler Datei durch (Task #1.2.0-05)
+     */
+    private fun performRestoreFromFile(uri: Uri, mode: RestoreMode) {
+        lifecycleScope.launch {
+            val progressDialog = android.app.ProgressDialog(this@SettingsActivity).apply {
+                setMessage("Wiederherstellen...")
+                setCancelable(false)
+                show()
+            }
+            
+            try {
+                Logger.d(TAG, "📥 Restoring from file: $uri (mode: $mode)")
+                val result = backupManager.restoreBackup(uri, mode)
+                
+                progressDialog.dismiss()
+                
+                if (result.success) {
+                    val message = result.message ?: "Wiederhergestellt: ${result.importedNotes} Notizen"
+                    showToast("✅ $message")
+                    
+                    // Refresh MainActivity's note list
+                    setResult(RESULT_OK)
+                    broadcastNotesChanged(result.importedNotes)
+                } else {
+                    showErrorDialog("Wiederherstellung fehlgeschlagen", result.error ?: "Unbekannter Fehler")
+                }
+            } catch (e: Exception) {
+                progressDialog.dismiss()
+                Logger.e(TAG, "Failed to restore from file", e)
+                showErrorDialog("Wiederherstellung fehlgeschlagen", e.message ?: "Unbekannter Fehler")
+            }
+        }
+    }
+    
+    /**
+     * Server-Restore mit Restore-Modi (v1.3.0)
+     */
+    private fun performRestoreFromServer(mode: RestoreMode) {
+        lifecycleScope.launch {
+            val progressDialog = android.app.ProgressDialog(this@SettingsActivity).apply {
+                setMessage("Wiederherstellen vom Server...")
+                setCancelable(false)
+                show()
+            }
+            
+            try {
+                Logger.d(TAG, "📥 Restoring from server (mode: $mode)")
+                
+                // Auto-Backup erstellen (Sicherheitsnetz)
+                val autoBackupUri = backupManager.createAutoBackup()
+                if (autoBackupUri == null) {
+                    Logger.w(TAG, "⚠️ Auto-backup failed, but continuing with restore")
+                }
+                
+                // Server-Restore durchführen
+                val webdavService = WebDavSyncService(this@SettingsActivity)
+                val result = withContext(Dispatchers.IO) {
+                    webdavService.restoreFromServer(mode)  // ✅ Pass mode parameter
+                }
+                
+                progressDialog.dismiss()
+                
+                if (result.isSuccess) {
+                    showToast("✅ Wiederhergestellt: ${result.restoredCount} Notizen")
+                    setResult(RESULT_OK)
+                    broadcastNotesChanged(result.restoredCount)
+                } else {
+                    showErrorDialog("Wiederherstellung fehlgeschlagen", result.errorMessage ?: "Unbekannter Fehler")
+                }
+            } catch (e: Exception) {
+                progressDialog.dismiss()
+                Logger.e(TAG, "Failed to restore from server", e)
+                showErrorDialog("Wiederherstellung fehlgeschlagen", e.message ?: "Unbekannter Fehler")
+            }
+        }
+    }
+    
+    /**
+     * Sendet Broadcast dass Notizen geändert wurden
+     */
+    private fun broadcastNotesChanged(count: Int = 0) {
+        val intent = Intent(dev.dettmer.simplenotes.sync.SyncWorker.ACTION_SYNC_COMPLETED)
+        intent.putExtra("success", true)
+        intent.putExtra("syncedCount", count)
+        LocalBroadcastManager.getInstance(this).sendBroadcast(intent)
+    }
+    
+    /**
+     * Updates visibility of manual sync button based on Auto-Sync toggle state
+     */
+    private fun updateMarkdownButtonVisibility() {
+        val autoSyncEnabled = switchMarkdownAutoSync.isChecked
+        val visibility = if (autoSyncEnabled) View.GONE else View.VISIBLE
+        
+        textViewManualSyncInfo.visibility = visibility
+        buttonManualMarkdownSync.visibility = visibility
+    }
+    
+    /**
+     * Performs manual Markdown sync (Export + Import)
+     * Called when manual sync button is clicked
+     */
+    private fun performManualMarkdownSync() {
+        lifecycleScope.launch {
+            var progressDialog: ProgressDialog? = null
+            try {
+                // Validierung
+                val serverUrl = prefs.getString(Constants.KEY_SERVER_URL, "")
+                val username = prefs.getString(Constants.KEY_USERNAME, "")
+                val password = prefs.getString(Constants.KEY_PASSWORD, "")
+                
+                if (serverUrl.isNullOrBlank() || username.isNullOrBlank() || password.isNullOrBlank()) {
+                    showToast("⚠️ Bitte zuerst WebDAV-Server konfigurieren")
+                    return@launch
+                }
+                
+                // Progress-Dialog
+                progressDialog = ProgressDialog(this@SettingsActivity).apply {
+                    setTitle("Markdown-Sync")
+                    setMessage("Synchronisiere Markdown-Dateien...")
+                    setCancelable(false)
+                    show()
+                }
+                
+                // Sync ausführen
+                val syncService = dev.dettmer.simplenotes.sync.WebDavSyncService(this@SettingsActivity)
+                val result = syncService.manualMarkdownSync()
+                
+                progressDialog.dismiss()
+                
+                // Erfolgs-Nachricht
+                val message = "✅ Sync abgeschlossen\n" +
+                    "📤 ${result.exportedCount} exportiert\n" +
+                    "📥 ${result.importedCount} importiert"
+                showToast(message)
+                
+                Logger.d(
+                    "SettingsActivity",
+                    "Manual markdown sync: exported=${result.exportedCount}, " +
+                        "imported=${result.importedCount}"
+                )
+                
+            } catch (e: Exception) {
+                progressDialog?.dismiss()
+                showToast("❌ Sync fehlgeschlagen: ${e.message}")
+                Logger.e("SettingsActivity", "Manual markdown sync failed", e)
+            }
+        }
+    }
+    
+    /**
+     * Zeigt Error-Dialog an
+     */
+    private fun showErrorDialog(title: String, message: String) {
+        AlertDialog.Builder(this)
+            .setTitle(title)
+            .setMessage(message)
+            .setPositiveButton("OK", null)
+            .show()
+    }
 }

android/app/src/main/java/dev/dettmer/simplenotes/backup/BackupManager.kt

@@ -0,0 +1,367 @@
+package dev.dettmer.simplenotes.backup
+
+import android.content.Context
+import android.net.Uri
+import com.google.gson.Gson
+import com.google.gson.GsonBuilder
+import dev.dettmer.simplenotes.BuildConfig
+import dev.dettmer.simplenotes.models.Note
+import dev.dettmer.simplenotes.storage.NotesStorage
+import dev.dettmer.simplenotes.utils.Logger
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import java.io.File
+import java.text.SimpleDateFormat
+import java.util.*
+
+/**
+ * BackupManager: Lokale Backup & Restore Funktionalität
+ * 
+ * Features:
+ * - Backup aller Notizen in JSON-Datei
+ * - Restore mit 3 Modi (Merge, Replace, Overwrite Duplicates)
+ * - Auto-Backup vor Restore (Sicherheitsnetz)
+ * - Backup-Validierung
+ */
+class BackupManager(private val context: Context) {
+    
+    companion object {
+        private const val TAG = "BackupManager"
+        private const val BACKUP_VERSION = 1
+        private const val AUTO_BACKUP_DIR = "auto_backups"
+        private const val AUTO_BACKUP_RETENTION_DAYS = 7
+    }
+    
+    private val storage = NotesStorage(context)
+    private val gson: Gson = GsonBuilder().setPrettyPrinting().create()
+    
+    /**
+     * Erstellt Backup aller Notizen
+     * 
+     * @param uri Output-URI (via Storage Access Framework)
+     * @return BackupResult mit Erfolg/Fehler Info
+     */
+    suspend fun createBackup(uri: Uri): BackupResult = withContext(Dispatchers.IO) {
+        return@withContext try {
+            Logger.d(TAG, "📦 Creating backup to: $uri")
+            
+            val allNotes = storage.loadAllNotes()
+            Logger.d(TAG, "   Found ${allNotes.size} notes to backup")
+            
+            val backupData = BackupData(
+                backupVersion = BACKUP_VERSION,
+                createdAt = System.currentTimeMillis(),
+                notesCount = allNotes.size,
+                appVersion = BuildConfig.VERSION_NAME,
+                notes = allNotes
+            )
+            
+            val jsonString = gson.toJson(backupData)
+            
+            context.contentResolver.openOutputStream(uri)?.use { outputStream ->
+                outputStream.write(jsonString.toByteArray())
+                Logger.d(TAG, "✅ Backup created successfully")
+            }
+            
+            BackupResult(
+                success = true,
+                notesCount = allNotes.size,
+                message = "Backup erstellt: ${allNotes.size} Notizen"
+            )
+            
+        } catch (e: Exception) {
+            Logger.e(TAG, "Failed to create backup", e)
+            BackupResult(
+                success = false,
+                error = "Backup fehlgeschlagen: ${e.message}"
+            )
+        }
+    }
+    
+    /**
+     * Erstellt automatisches Backup (vor Restore)
+     * Gespeichert in app-internem Storage
+     * 
+     * @return Uri des Auto-Backups oder null bei Fehler
+     */
+    suspend fun createAutoBackup(): Uri? = withContext(Dispatchers.IO) {
+        return@withContext try {
+            val autoBackupDir = File(context.filesDir, AUTO_BACKUP_DIR).apply {
+                if (!exists()) mkdirs()
+            }
+            
+            val timestamp = SimpleDateFormat("yyyy-MM-dd_HHmmss", Locale.US)
+                .format(Date())
+            val filename = "auto_backup_before_restore_$timestamp.json"
+            val file = File(autoBackupDir, filename)
+            
+            Logger.d(TAG, "📦 Creating auto-backup: ${file.absolutePath}")
+            
+            val allNotes = storage.loadAllNotes()
+            val backupData = BackupData(
+                backupVersion = BACKUP_VERSION,
+                createdAt = System.currentTimeMillis(),
+                notesCount = allNotes.size,
+                appVersion = BuildConfig.VERSION_NAME,
+                notes = allNotes
+            )
+            
+            file.writeText(gson.toJson(backupData))
+            
+            // Cleanup alte Auto-Backups
+            cleanupOldAutoBackups(autoBackupDir)
+            
+            Logger.d(TAG, "✅ Auto-backup created: ${file.absolutePath}")
+            Uri.fromFile(file)
+            
+        } catch (e: Exception) {
+            Logger.e(TAG, "Failed to create auto-backup", e)
+            null
+        }
+    }
+    
+    /**
+     * Stellt Notizen aus Backup wieder her
+     * 
+     * @param uri Backup-Datei URI
+     * @param mode Wiederherstellungs-Modus (Merge/Replace/Overwrite)
+     * @return RestoreResult mit Details
+     */
+    suspend fun restoreBackup(uri: Uri, mode: RestoreMode): RestoreResult = withContext(Dispatchers.IO) {
+        return@withContext try {
+            Logger.d(TAG, "📥 Restoring backup from: $uri (mode: $mode)")
+            
+            // 1. Backup-Datei lesen
+            val jsonString = context.contentResolver.openInputStream(uri)?.use { inputStream ->
+                inputStream.bufferedReader().use { it.readText() }
+            } ?: return@withContext RestoreResult(
+                success = false,
+                error = "Datei konnte nicht gelesen werden"
+            )
+            
+            // 2. Backup validieren & parsen
+            val validationResult = validateBackup(jsonString)
+            if (!validationResult.isValid) {
+                return@withContext RestoreResult(
+                    success = false,
+                    error = validationResult.errorMessage ?: "Ungültige Backup-Datei"
+                )
+            }
+            
+            val backupData = gson.fromJson(jsonString, BackupData::class.java)
+            Logger.d(TAG, "   Backup valid: ${backupData.notesCount} notes, version ${backupData.backupVersion}")
+            
+            // 3. Auto-Backup erstellen (Sicherheitsnetz)
+            val autoBackupUri = createAutoBackup()
+            if (autoBackupUri == null) {
+                Logger.w(TAG, "⚠️ Auto-backup failed, but continuing with restore")
+            }
+            
+            // 4. Restore durchführen (je nach Modus)
+            val result = when (mode) {
+                RestoreMode.MERGE -> restoreMerge(backupData.notes)
+                RestoreMode.REPLACE -> restoreReplace(backupData.notes)
+                RestoreMode.OVERWRITE_DUPLICATES -> restoreOverwriteDuplicates(backupData.notes)
+            }
+            
+            Logger.d(TAG, "✅ Restore completed: ${result.importedNotes} imported, ${result.skippedNotes} skipped")
+            result
+            
+        } catch (e: Exception) {
+            Logger.e(TAG, "Failed to restore backup", e)
+            RestoreResult(
+                success = false,
+                error = "Wiederherstellung fehlgeschlagen: ${e.message}"
+            )
+        }
+    }
+    
+    /**
+     * Validiert Backup-Datei
+     */
+    private fun validateBackup(jsonString: String): ValidationResult {
+        return try {
+            val backupData = gson.fromJson(jsonString, BackupData::class.java)
+            
+            // Version kompatibel?
+            if (backupData.backupVersion > BACKUP_VERSION) {
+                return ValidationResult(
+                    isValid = false,
+                    errorMessage = "Backup-Version nicht unterstützt " +
+                        "(v${backupData.backupVersion} benötigt v${BACKUP_VERSION}+)"
+                )
+            }
+            
+            // Notizen-Array vorhanden?
+            if (backupData.notes.isEmpty()) {
+                return ValidationResult(
+                    isValid = false,
+                    errorMessage = "Backup enthält keine Notizen"
+                )
+            }
+            
+            // Alle Notizen haben ID, title, content?
+            val invalidNotes = backupData.notes.filter { note ->
+                note.id.isBlank() || note.title.isBlank()
+            }
+            
+            if (invalidNotes.isNotEmpty()) {
+                return ValidationResult(
+                    isValid = false,
+                    errorMessage = "Backup enthält ${invalidNotes.size} ungültige Notizen"
+                )
+            }
+            
+            ValidationResult(isValid = true)
+            
+        } catch (e: Exception) {
+            ValidationResult(
+                isValid = false,
+                errorMessage = "Backup-Datei beschädigt oder ungültig: ${e.message}"
+            )
+        }
+    }
+    
+    /**
+     * Restore-Modus: MERGE
+     * Fügt neue Notizen hinzu, behält bestehende
+     */
+    private fun restoreMerge(backupNotes: List<Note>): RestoreResult {
+        val existingNotes = storage.loadAllNotes()
+        val existingIds = existingNotes.map { it.id }.toSet()
+        
+        val newNotes = backupNotes.filter { it.id !in existingIds }
+        val skippedNotes = backupNotes.size - newNotes.size
+        
+        newNotes.forEach { note ->
+            storage.saveNote(note)
+        }
+        
+        return RestoreResult(
+            success = true,
+            importedNotes = newNotes.size,
+            skippedNotes = skippedNotes,
+            message = "${newNotes.size} neue Notizen importiert, $skippedNotes übersprungen"
+        )
+    }
+    
+    /**
+     * Restore-Modus: REPLACE
+     * Löscht alle bestehenden Notizen, importiert Backup
+     */
+    private fun restoreReplace(backupNotes: List<Note>): RestoreResult {
+        // Alle bestehenden Notizen löschen
+        storage.deleteAllNotes()
+        
+        // Backup-Notizen importieren
+        backupNotes.forEach { note ->
+            storage.saveNote(note)
+        }
+        
+        return RestoreResult(
+            success = true,
+            importedNotes = backupNotes.size,
+            skippedNotes = 0,
+            message = "Alle Notizen ersetzt: ${backupNotes.size} importiert"
+        )
+    }
+    
+    /**
+     * Restore-Modus: OVERWRITE_DUPLICATES
+     * Backup überschreibt bei ID-Konflikten
+     */
+    private fun restoreOverwriteDuplicates(backupNotes: List<Note>): RestoreResult {
+        val existingNotes = storage.loadAllNotes()
+        val existingIds = existingNotes.map { it.id }.toSet()
+        
+        val newNotes = backupNotes.filter { it.id !in existingIds }
+        val overwrittenNotes = backupNotes.filter { it.id in existingIds }
+        
+        // Alle Backup-Notizen speichern (überschreibt automatisch)
+        backupNotes.forEach { note ->
+            storage.saveNote(note)
+        }
+        
+        return RestoreResult(
+            success = true,
+            importedNotes = newNotes.size,
+            skippedNotes = 0,
+            overwrittenNotes = overwrittenNotes.size,
+            message = "${newNotes.size} neu, ${overwrittenNotes.size} überschrieben"
+        )
+    }
+    
+    /**
+     * Löscht Auto-Backups älter als RETENTION_DAYS
+     */
+    private fun cleanupOldAutoBackups(autoBackupDir: File) {
+        try {
+            val retentionTimeMs = AUTO_BACKUP_RETENTION_DAYS * 24 * 60 * 60 * 1000L
+            val cutoffTime = System.currentTimeMillis() - retentionTimeMs
+            
+            autoBackupDir.listFiles()?.forEach { file ->
+                if (file.lastModified() < cutoffTime) {
+                    Logger.d(TAG, "🗑️ Deleting old auto-backup: ${file.name}")
+                    file.delete()
+                }
+            }
+        } catch (e: Exception) {
+            Logger.e(TAG, "Failed to cleanup old backups", e)
+        }
+    }
+}
+
+/**
+ * Backup-Daten Struktur (JSON)
+ * NOTE: Property names use @SerializedName for JSON compatibility with snake_case
+ */
+data class BackupData(
+    @com.google.gson.annotations.SerializedName("backup_version")
+    val backupVersion: Int,
+    @com.google.gson.annotations.SerializedName("created_at")
+    val createdAt: Long,
+    @com.google.gson.annotations.SerializedName("notes_count")
+    val notesCount: Int,
+    @com.google.gson.annotations.SerializedName("app_version")
+    val appVersion: String,
+    val notes: List<Note>
+)
+
+/**
+ * Wiederherstellungs-Modi
+ */
+enum class RestoreMode {
+    MERGE,                  // Bestehende + Neue (Standard)
+    REPLACE,                // Alles löschen + Importieren
+    OVERWRITE_DUPLICATES    // Backup überschreibt bei ID-Konflikten
+}
+
+/**
+ * Backup-Ergebnis
+ */
+data class BackupResult(
+    val success: Boolean,
+    val notesCount: Int = 0,
+    val message: String? = null,
+    val error: String? = null
+)
+
+/**
+ * Restore-Ergebnis
+ */
+data class RestoreResult(
+    val success: Boolean,
+    val importedNotes: Int = 0,
+    val skippedNotes: Int = 0,
+    val overwrittenNotes: Int = 0,
+    val message: String? = null,
+    val error: String? = null
+)
+
+/**
+ * Validierungs-Ergebnis
+ */
+data class ValidationResult(
+    val isValid: Boolean,
+    val errorMessage: String? = null
+)

android/app/src/main/java/dev/dettmer/simplenotes/models/DeletionTracker.kt

@@ -0,0 +1,81 @@
+package dev.dettmer.simplenotes.models
+
+import dev.dettmer.simplenotes.utils.Logger
+import org.json.JSONArray
+import org.json.JSONObject
+
+data class DeletionRecord(
+    val id: String,
+    val deletedAt: Long,
+    val deviceId: String
+)
+
+data class DeletionTracker(
+    val version: Int = 1,
+    val deletedNotes: MutableList<DeletionRecord> = mutableListOf()
+) {
+    fun addDeletion(noteId: String, deviceId: String) {
+        if (!deletedNotes.any { it.id == noteId }) {
+            deletedNotes.add(DeletionRecord(noteId, System.currentTimeMillis(), deviceId))
+        }
+    }
+    
+    fun isDeleted(noteId: String): Boolean {
+        return deletedNotes.any { it.id == noteId }
+    }
+    
+    fun getDeletionTimestamp(noteId: String): Long? {
+        return deletedNotes.find { it.id == noteId }?.deletedAt
+    }
+    
+    fun removeDeletion(noteId: String) {
+        deletedNotes.removeIf { it.id == noteId }
+    }
+    
+    fun toJson(): String {
+        val jsonObject = JSONObject()
+        jsonObject.put("version", version)
+        
+        val notesArray = JSONArray()
+        for (record in deletedNotes) {
+            val recordObj = JSONObject()
+            recordObj.put("id", record.id)
+            recordObj.put("deletedAt", record.deletedAt)
+            recordObj.put("deviceId", record.deviceId)
+            notesArray.put(recordObj)
+        }
+        jsonObject.put("deletedNotes", notesArray)
+        
+        return jsonObject.toString(2)  // Pretty print with 2-space indent
+    }
+    
+    companion object {
+        private const val TAG = "DeletionTracker"
+        
+        fun fromJson(json: String): DeletionTracker? {
+            return try {
+                val jsonObject = JSONObject(json)
+                val version = jsonObject.optInt("version", 1)
+                val deletedNotes = mutableListOf<DeletionRecord>()
+                
+                val notesArray = jsonObject.optJSONArray("deletedNotes")
+                if (notesArray != null) {
+                    for (i in 0 until notesArray.length()) {
+                        val recordObj = notesArray.getJSONObject(i)
+                        val record = DeletionRecord(
+                            id = recordObj.getString("id"),
+                            deletedAt = recordObj.getLong("deletedAt"),
+                            deviceId = recordObj.getString("deviceId")
+                        )
+                        deletedNotes.add(record)
+                    }
+                }
+                
+                DeletionTracker(version, deletedNotes)
+            } catch (e: Exception) {
+                Logger.w(TAG, "Failed to parse DeletionTracker JSON: ${e.message}")
+                null
+            }
+        }
+    }
+}

android/app/src/main/java/dev/dettmer/simplenotes/models/Note.kt

@@ -1,5 +1,10 @@
 package dev.dettmer.simplenotes.models
 
+import dev.dettmer.simplenotes.utils.Logger
+import java.text.SimpleDateFormat
+import java.util.Date
+import java.util.Locale
+import java.util.TimeZone
 import java.util.UUID
 
 data class Note(
@@ -25,15 +30,111 @@ data class Note(
         """.trimIndent()
     }
     
+    /**
+     * Konvertiert Note zu Markdown mit YAML Frontmatter (Task #1.2.0-08)
+     * Format kompatibel mit Obsidian, Joplin, Typora
+     */
+    fun toMarkdown(): String {
+        return """
+---
+id: $id
+created: ${formatISO8601(createdAt)}
+updated: ${formatISO8601(updatedAt)}
+device: $deviceId
+---
+
+# $title
+
+$content
+        """.trimIndent()
+    }
+    
     companion object {
+        private const val TAG = "Note"
+        
         fun fromJson(json: String): Note? {
             return try {
                 val gson = com.google.gson.Gson()
                 gson.fromJson(json, Note::class.java)
             } catch (e: Exception) {
+                Logger.w(TAG, "Failed to parse JSON: ${e.message}")
                 null
             }
         }
+        
+        /**
+         * Parst Markdown zurück zu Note-Objekt (Task #1.2.0-09)
+         * 
+         * @param md Markdown-String mit YAML Frontmatter
+         * @return Note-Objekt oder null bei Parse-Fehler
+         */
+        fun fromMarkdown(md: String): Note? {
+            return try {
+                // Parse YAML Frontmatter + Markdown Content
+                val frontmatterRegex = Regex("^---\\n(.+?)\\n---\\n(.*)$", RegexOption.DOT_MATCHES_ALL)
+                val match = frontmatterRegex.find(md) ?: return null
+                
+                val yamlBlock = match.groupValues[1]
+                val contentBlock = match.groupValues[2]
+                
+                // Parse YAML (einfach per String-Split für MVP)
+                val metadata = yamlBlock.lines()
+                    .mapNotNull { line ->
+                        val parts = line.split(":", limit = 2)
+                        if (parts.size == 2) {
+                            parts[0].trim() to parts[1].trim()
+                        } else null
+                    }.toMap()
+                
+                // Extract title from first # heading
+                val title = contentBlock.lines()
+                    .firstOrNull { it.startsWith("# ") }
+                    ?.removePrefix("# ")?.trim() ?: "Untitled"
+                
+                // Extract content (everything after heading)
+                val content = contentBlock
+                    .substringAfter("# $title\n\n", "")
+                    .trim()
+                
+                Note(
+                    id = metadata["id"] ?: UUID.randomUUID().toString(),
+                    title = title,
+                    content = content,
+                    createdAt = parseISO8601(metadata["created"] ?: ""),
+                    updatedAt = parseISO8601(metadata["updated"] ?: ""),
+                    deviceId = metadata["device"] ?: "desktop",
+                    syncStatus = SyncStatus.SYNCED  // Annahme: Vom Server importiert
+                )
+            } catch (e: Exception) {
+                Logger.w(TAG, "Failed to parse Markdown: ${e.message}")
+                null
+            }
+        }
+        
+        /**
+         * Formatiert Timestamp zu ISO8601 (Task #1.2.0-10)
+         * Format: 2024-12-21T18:00:00Z (UTC)
+         */
+        private fun formatISO8601(timestamp: Long): String {
+            val sdf = SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'", Locale.US)
+            sdf.timeZone = TimeZone.getTimeZone("UTC")
+            return sdf.format(Date(timestamp))
+        }
+        
+        /**
+         * Parst ISO8601 zurück zu Timestamp (Task #1.2.0-10)
+         * Fallback: Aktueller Timestamp bei Fehler
+         */
+        private fun parseISO8601(dateString: String): Long {
+            return try {
+                val sdf = SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'", Locale.US)
+                sdf.timeZone = TimeZone.getTimeZone("UTC")
+                sdf.parse(dateString)?.time ?: System.currentTimeMillis()
+            } catch (e: Exception) {
+                Logger.w(TAG, "Failed to parse ISO8601 date '$dateString': ${e.message}")
+                System.currentTimeMillis()  // Fallback
+            }
+        }
     }
 }
 

android/app/src/main/java/dev/dettmer/simplenotes/storage/NotesStorage.kt

@@ -1,11 +1,18 @@
 package dev.dettmer.simplenotes.storage
 
 import android.content.Context
+import dev.dettmer.simplenotes.models.DeletionTracker
 import dev.dettmer.simplenotes.models.Note
+import dev.dettmer.simplenotes.utils.DeviceIdGenerator
+import dev.dettmer.simplenotes.utils.Logger
 import java.io.File
 
 class NotesStorage(private val context: Context) {
     
+    companion object {
+        private const val TAG = "NotesStorage"
+    }
+    
     private val notesDir: File = File(context.filesDir, "notes").apply {
         if (!exists()) mkdirs()
     }
@@ -34,19 +41,89 @@ class NotesStorage(private val context: Context) {
     
     fun deleteNote(id: String): Boolean {
         val file = File(notesDir, "$id.json")
-        return file.delete()
+        val deleted = file.delete()
+        
+        if (deleted) {
+            Logger.d(TAG, "🗑️ Deleted note: $id")
+            
+            // Track deletion to prevent zombie notes
+            val deviceId = DeviceIdGenerator.getDeviceId(context)
+            trackDeletion(id, deviceId)
+        }
+        
+        return deleted
     }
     
     fun deleteAllNotes(): Boolean {
         return try {
-            notesDir.listFiles()
-                ?.filter { it.extension == "json" }
-                ?.forEach { it.delete() }
+            val notes = loadAllNotes()
+            val deviceId = DeviceIdGenerator.getDeviceId(context)
+            
+            for (note in notes) {
+                deleteNote(note.id)  // Uses trackDeletion() automatically
+            }
+            
+            Logger.d(TAG, "🗑️ Deleted all notes (${notes.size} notes)")
             true
         } catch (e: Exception) {
+            Logger.e(TAG, "Failed to delete all notes", e)
             false
         }
     }
     
+    // === Deletion Tracking ===
+    
+    private fun getDeletionTrackerFile(): File {
+        return File(context.filesDir, "deleted_notes.json")
+    }
+    
+    fun loadDeletionTracker(): DeletionTracker {
+        val file = getDeletionTrackerFile()
+        if (!file.exists()) {
+            return DeletionTracker()
+        }
+        
+        return try {
+            val json = file.readText()
+            DeletionTracker.fromJson(json) ?: DeletionTracker()
+        } catch (e: Exception) {
+            Logger.e(TAG, "Failed to load deletion tracker", e)
+            DeletionTracker()
+        }
+    }
+    
+    fun saveDeletionTracker(tracker: DeletionTracker) {
+        try {
+            val file = getDeletionTrackerFile()
+            file.writeText(tracker.toJson())
+            
+            if (tracker.deletedNotes.size > 1000) {
+                Logger.w(TAG, "⚠️ Deletion tracker large: ${tracker.deletedNotes.size} entries")
+            }
+            
+            Logger.d(TAG, "✅ Deletion tracker saved (${tracker.deletedNotes.size} entries)")
+        } catch (e: Exception) {
+            Logger.e(TAG, "Failed to save deletion tracker", e)
+        }
+    }
+    
+    fun trackDeletion(noteId: String, deviceId: String) {
+        val tracker = loadDeletionTracker()
+        tracker.addDeletion(noteId, deviceId)
+        saveDeletionTracker(tracker)
+        Logger.d(TAG, "📝 Tracked deletion: $noteId")
+    }
+    
+    fun isNoteDeleted(noteId: String): Boolean {
+        val tracker = loadDeletionTracker()
+        return tracker.isDeleted(noteId)
+    }
+    
+    fun clearDeletionTracker() {
+        saveDeletionTracker(DeletionTracker())
+        Logger.d(TAG, "🗑️ Deletion tracker cleared")
+    }
+
+    
     fun getNotesDir(): File = notesDir
 }

android/app/src/main/java/dev/dettmer/simplenotes/sync/NetworkMonitor.kt

@@ -227,7 +227,11 @@ class NetworkMonitor(private val context: Context) {
             if (isWifi) {
                 lastConnectedNetworkId = activeNetwork.toString()
                 Logger.d(TAG, "    ✅ Initial WiFi network: $lastConnectedNetworkId")
-                Logger.d(TAG, "    📡 WiFi already connected at startup - onAvailable() will only trigger on network change")
+                Logger.d(
+                    TAG,
+                    "    📡 WiFi already connected at startup - " +
+                        "onAvailable() will only trigger on network change"
+                )
             } else {
                 lastConnectedNetworkId = null
                 Logger.d(TAG, "    ⚠️ Not on WiFi at startup")
@@ -268,7 +272,7 @@ class NetworkMonitor(private val context: Context) {
             connectivityManager.unregisterNetworkCallback(networkCallback)
             Logger.d(TAG, "✅ WiFi monitoring stopped")
         } catch (e: Exception) {
-            // Already unregistered
+            Logger.w(TAG, "NetworkCallback already unregistered: ${e.message}")
         }
     }
 }

android/app/src/main/java/dev/dettmer/simplenotes/sync/SyncStateManager.kt

@@ -0,0 +1,129 @@
+package dev.dettmer.simplenotes.sync
+
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.MutableLiveData
+import dev.dettmer.simplenotes.utils.Logger
+
+/**
+ * 🔄 v1.3.1: Zentrale Verwaltung des Sync-Status
+ * 
+ * Verhindert doppelte Syncs und informiert die UI über den aktuellen Status.
+ * Thread-safe Singleton mit LiveData für UI-Reaktivität.
+ */
+object SyncStateManager {
+    
+    private const val TAG = "SyncStateManager"
+    
+    /**
+     * Mögliche Sync-Zustände
+     */
+    enum class SyncState {
+        IDLE,           // Kein Sync aktiv
+        SYNCING,        // Sync läuft gerade
+        COMPLETED,      // Sync erfolgreich abgeschlossen (kurz anzeigen)
+        ERROR           // Sync fehlgeschlagen (kurz anzeigen)
+    }
+    
+    /**
+     * Detaillierte Sync-Informationen für UI
+     */
+    data class SyncStatus(
+        val state: SyncState = SyncState.IDLE,
+        val message: String? = null,
+        val source: String? = null,  // "manual", "auto", "pullToRefresh", "background"
+        val timestamp: Long = System.currentTimeMillis()
+    )
+    
+    // Private mutable LiveData
+    private val _syncStatus = MutableLiveData(SyncStatus())
+    
+    // Public immutable LiveData für Observer
+    val syncStatus: LiveData<SyncStatus> = _syncStatus
+    
+    // Lock für Thread-Sicherheit
+    private val lock = Any()
+    
+    /**
+     * Prüft ob gerade ein Sync läuft
+     */
+    val isSyncing: Boolean
+        get() = _syncStatus.value?.state == SyncState.SYNCING
+    
+    /**
+     * Versucht einen Sync zu starten.
+     * @return true wenn Sync gestartet werden kann, false wenn bereits einer läuft
+     */
+    fun tryStartSync(source: String): Boolean {
+        synchronized(lock) {
+            if (isSyncing) {
+                Logger.d(TAG, "⚠️ Sync already in progress, rejecting new sync from: $source")
+                return false
+            }
+            
+            Logger.d(TAG, "🔄 Starting sync from: $source")
+            _syncStatus.postValue(
+                SyncStatus(
+                    state = SyncState.SYNCING,
+                    message = "Synchronisiere...",
+                    source = source
+                )
+            )
+            return true
+        }
+    }
+    
+    /**
+     * Markiert Sync als erfolgreich abgeschlossen
+     */
+    fun markCompleted(message: String? = null) {
+        synchronized(lock) {
+            val currentSource = _syncStatus.value?.source
+            Logger.d(TAG, "✅ Sync completed from: $currentSource")
+            _syncStatus.postValue(
+                SyncStatus(
+                    state = SyncState.COMPLETED,
+                    message = message,
+                    source = currentSource
+                )
+            )
+        }
+    }
+    
+    /**
+     * Markiert Sync als fehlgeschlagen
+     */
+    fun markError(errorMessage: String?) {
+        synchronized(lock) {
+            val currentSource = _syncStatus.value?.source
+            Logger.e(TAG, "❌ Sync failed from: $currentSource - $errorMessage")
+            _syncStatus.postValue(
+                SyncStatus(
+                    state = SyncState.ERROR,
+                    message = errorMessage,
+                    source = currentSource
+                )
+            )
+        }
+    }
+    
+    /**
+     * Setzt Status zurück auf IDLE
+     */
+    fun reset() {
+        synchronized(lock) {
+            _syncStatus.postValue(SyncStatus())
+        }
+    }
+    
+    /**
+     * Aktualisiert die Nachricht während des Syncs (z.B. Progress)
+     */
+    fun updateMessage(message: String) {
+        synchronized(lock) {
+            val current = _syncStatus.value ?: return
+            if (current.state == SyncState.SYNCING) {
+                _syncStatus.postValue(current.copy(message = message))
+            }
+        }
+    }
+}

android/app/src/main/java/dev/dettmer/simplenotes/sync/SyncWorker.kt

@@ -117,7 +117,11 @@ class SyncWorker(
             
             if (BuildConfig.DEBUG) {
                 Logger.d(TAG, "📍 Step 4: Processing result")
-                Logger.d(TAG, "📦 Sync result: success=${result.isSuccess}, count=${result.syncedCount}, error=${result.errorMessage}")
+                Logger.d(
+                    TAG,
+                    "📦 Sync result: success=${result.isSuccess}, " +
+                        "count=${result.syncedCount}, error=${result.errorMessage}"
+                )
             }
             
             if (result.isSuccess) {

android/app/src/main/java/dev/dettmer/simplenotes/sync/WifiSyncReceiver.kt

@@ -28,6 +28,7 @@ class WifiSyncReceiver : BroadcastReceiver() {
         }
     }
     
+    @Suppress("ReturnCount") // Early returns for WiFi validation checks
     private fun isConnectedToHomeWifi(context: Context): Boolean {
         val prefs = context.getSharedPreferences(Constants.PREFS_NAME, Context.MODE_PRIVATE)
         val homeSSID = prefs.getString(Constants.KEY_HOME_SSID, null) ?: return false

android/app/src/main/java/dev/dettmer/simplenotes/utils/Constants.kt

@@ -19,6 +19,17 @@ object Constants {
     const val PREF_SYNC_INTERVAL_MINUTES = "sync_interval_minutes"
     const val DEFAULT_SYNC_INTERVAL_MINUTES = 30L
     
+    // 🔥 v1.2.0: Markdown Export/Import
+    const val KEY_MARKDOWN_EXPORT = "markdown_export_enabled"
+    const val KEY_MARKDOWN_AUTO_IMPORT = "markdown_auto_import_enabled"
+    
+    // 🔥 v1.3.0: Performance & Multi-Device Sync
+    const val KEY_ALWAYS_CHECK_SERVER = "always_check_server"
+    const val KEY_ALWAYS_DELETE_FROM_SERVER = "always_delete_from_server"
+    
+    // 🔥 v1.3.1: Debug & Logging
+    const val KEY_FILE_LOGGING_ENABLED = "file_logging_enabled"
+    
     // WorkManager
     const val SYNC_WORK_TAG = "notes_sync"
     const val SYNC_DELAY_SECONDS = 5L

android/app/src/main/java/dev/dettmer/simplenotes/utils/Extensions.kt

@@ -7,6 +7,9 @@ import java.util.Date
 import java.util.Locale
 import java.util.concurrent.TimeUnit
 
+private const val DAYS_THRESHOLD = 7L
+private const val TRUNCATE_SUFFIX_LENGTH = 3
+
 // Toast Extensions
 fun Context.showToast(message: String, duration: Int = Toast.LENGTH_SHORT) {
     Toast.makeText(this, message, duration).show()
@@ -27,7 +30,7 @@ fun Long.toReadableTime(): String {
             val hours = TimeUnit.MILLISECONDS.toHours(diff)
             "Vor $hours Std"
         }
-        diff < TimeUnit.DAYS.toMillis(7) -> {
+        diff < TimeUnit.DAYS.toMillis(DAYS_THRESHOLD) -> {
             val days = TimeUnit.MILLISECONDS.toDays(diff)
             "Vor $days Tagen"
         }
@@ -41,7 +44,7 @@ fun Long.toReadableTime(): String {
 // Truncate long strings
 fun String.truncate(maxLength: Int): String {
     return if (length > maxLength) {
-        substring(0, maxLength - 3) + "..."
+        substring(0, maxLength - TRUNCATE_SUFFIX_LENGTH) + "..."
     } else {
         this
     }

android/app/src/main/java/dev/dettmer/simplenotes/utils/Logger.kt

@@ -5,7 +5,6 @@ import android.util.Log
 import dev.dettmer.simplenotes.BuildConfig
 import java.io.File
 import java.io.FileWriter
-import java.io.PrintWriter
 import java.text.SimpleDateFormat
 import java.util.*
 
@@ -15,10 +14,34 @@ import java.util.*
  */
 object Logger {
     
+    private const val MAX_LOG_ENTRIES = 500 // Nur letzte 500 Einträge
+    
     private var fileLoggingEnabled = false
     private var logFile: File? = null
+    private var appContext: Context? = null
     private val dateFormat = SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS", Locale.getDefault())
-    private val maxLogEntries = 500 // Nur letzte 500 Einträge
+    
+    /**
+     * Setzt den File-Logging Status (für UI Toggle)
+     */
+    fun setFileLoggingEnabled(enabled: Boolean) {
+        fileLoggingEnabled = enabled
+        if (!enabled) {
+            logFile = null
+        }
+    }
+    
+    /**
+     * Gibt zurück, ob File-Logging aktiviert ist
+     */
+    fun isFileLoggingEnabled(): Boolean = fileLoggingEnabled
+    
+    /**
+     * Initialisiert den Logger mit App-Context
+     */
+    fun init(context: Context) {
+        appContext = context.applicationContext
+    }
     
     /**
      * Aktiviert File-Logging für Debugging
@@ -50,11 +73,47 @@ object Logger {
      */
     fun getLogFile(): File? = logFile
     
+    /**
+     * Gibt Log-Datei mit Context zurück (für SettingsActivity)
+     */
+    fun getLogFile(context: Context): File? {
+        if (logFile == null && fileLoggingEnabled) {
+            logFile = File(context.filesDir, "simplenotes_debug.log")
+        }
+        return logFile
+    }
+    
+    /**
+     * Löscht die Log-Datei
+     */
+    fun clearLogFile(context: Context): Boolean {
+        return try {
+            val file = File(context.filesDir, "simplenotes_debug.log")
+            if (file.exists()) {
+                file.delete()
+                logFile = null
+                true
+            } else {
+                false
+            }
+        } catch (e: Exception) {
+            Log.e("Logger", "Failed to clear log file", e)
+            false
+        }
+    }
+    
     /**
      * Schreibt Log-Eintrag in Datei
      */
     private fun writeToFile(level: String, tag: String, message: String, throwable: Throwable? = null) {
-        if (!fileLoggingEnabled || logFile == null) return
+        if (!fileLoggingEnabled) return
+        
+        // Lazy-init logFile mit appContext
+        if (logFile == null && appContext != null) {
+            logFile = File(appContext!!.filesDir, "simplenotes_debug.log")
+        }
+        
+        if (logFile == null) return
         
         try {
             val timestamp = dateFormat.format(Date())
@@ -80,13 +139,13 @@ object Logger {
     }
     
     /**
-     * Begrenzt Log-Datei auf maxLogEntries
+     * Begrenzt Log-Datei auf MAX_LOG_ENTRIES
      */
     private fun trimLogFile() {
         try {
             val lines = logFile?.readLines() ?: return
-            if (lines.size > maxLogEntries) {
-                val trimmed = lines.takeLast(maxLogEntries)
+            if (lines.size > MAX_LOG_ENTRIES) {
+                val trimmed = lines.takeLast(MAX_LOG_ENTRIES)
                 logFile?.writeText(trimmed.joinToString("\n") + "\n")
             }
         } catch (e: Exception) {

android/app/src/main/java/dev/dettmer/simplenotes/utils/NotificationHelper.kt

@@ -20,6 +20,7 @@ object NotificationHelper {
     private const val CHANNEL_DESCRIPTION = "Benachrichtigungen über Sync-Status"
     private const val NOTIFICATION_ID = 1001
     private const val SYNC_NOTIFICATION_ID = 2
+    private const val AUTO_CANCEL_TIMEOUT_MS = 30_000L
     
     /**
      * Erstellt Notification Channel (Android 8.0+)
@@ -286,7 +287,7 @@ object NotificationHelper {
         Handler(Looper.getMainLooper()).postDelayed({
             manager.cancel(SYNC_NOTIFICATION_ID)
             Logger.d(TAG, "🗑️ Auto-cancelled error notification after 30s timeout")
-        }, 30_000)
+        }, AUTO_CANCEL_TIMEOUT_MS)
     }
     
     /**

android/app/src/main/java/dev/dettmer/simplenotes/utils/SyncException.kt

@@ -0,0 +1,21 @@
+package dev.dettmer.simplenotes.utils
+
+/**
+ * Exception für Sync-spezifische Fehler
+ * 
+ * Verwendet anstelle von generischen Exceptions für bessere
+ * Fehlerbehandlung und klarere Fehlermeldungen.
+ */
+class SyncException(
+    message: String,
+    cause: Throwable? = null
+) : Exception(message, cause)
+
+/**
+ * Exception für Validierungsfehler
+ * 
+ * Verwendet für ungültige Eingaben oder Konfigurationsfehler.
+ */
+class ValidationException(
+    message: String
+) : IllegalArgumentException(message)

android/app/src/main/java/dev/dettmer/simplenotes/utils/UrlValidator.kt

@@ -8,6 +8,16 @@ import java.net.URL
  */
 object UrlValidator {
     
+    // RFC 1918 Private IP Ranges
+    private const val PRIVATE_CLASS_A_FIRST_OCTET = 10
+    private const val PRIVATE_CLASS_B_FIRST_OCTET = 172
+    private const val PRIVATE_CLASS_B_SECOND_OCTET_MIN = 16
+    private const val PRIVATE_CLASS_B_SECOND_OCTET_MAX = 31
+    private const val PRIVATE_CLASS_C_FIRST_OCTET = 192
+    private const val PRIVATE_CLASS_C_SECOND_OCTET = 168
+    private const val LOCALHOST_FIRST_OCTET = 127
+    private const val OCTET_MAX_VALUE = 255
+    
     /**
      * Prüft ob eine URL eine lokale/private Adresse ist
      * Erlaubt:
@@ -17,6 +27,7 @@ object UrlValidator {
      * - 127.x.x.x (Localhost)
      * - .local domains (mDNS/Bonjour)
      */
+    @Suppress("ReturnCount") // Early returns for validation checks are clearer
     fun isLocalUrl(url: String): Boolean {
         return try {
             val parsedUrl = URL(url)
@@ -40,25 +51,29 @@ object UrlValidator {
                 val octets = match.groupValues.drop(1).map { it.toInt() }
                 
                 // Validate octets are in range 0-255
-                if (octets.any { it > 255 }) {
+                if (octets.any { it > OCTET_MAX_VALUE }) {
                     return false
                 }
                 
-                val (o1, o2, o3, o4) = octets
+                // Extract octets individually (destructuring with 4 elements triggers detekt warning)
+                val o1 = octets[0]
+                val o2 = octets[1]
                 
                 // Check RFC 1918 private IP ranges
                 return when {
                     // 10.0.0.0/8 (10.0.0.0 - 10.255.255.255)
-                    o1 == 10 -> true
+                    o1 == PRIVATE_CLASS_A_FIRST_OCTET -> true
                     
                     // 172.16.0.0/12 (172.16.0.0 - 172.31.255.255)
-                    o1 == 172 && o2 in 16..31 -> true
+                    o1 == PRIVATE_CLASS_B_FIRST_OCTET &&
+                        o2 in PRIVATE_CLASS_B_SECOND_OCTET_MIN..PRIVATE_CLASS_B_SECOND_OCTET_MAX -> true
                     
                     // 192.168.0.0/16 (192.168.0.0 - 192.168.255.255)
-                    o1 == 192 && o2 == 168 -> true
+                    o1 == PRIVATE_CLASS_C_FIRST_OCTET &&
+                        o2 == PRIVATE_CLASS_C_SECOND_OCTET -> true
                     
                     // 127.0.0.0/8 (Localhost)
-                    o1 == 127 -> true
+                    o1 == LOCALHOST_FIRST_OCTET -> true
                     
                     else -> false
                 }
@@ -67,7 +82,7 @@ object UrlValidator {
             // Not a recognized local address
             false
         } catch (e: Exception) {
-            // Invalid URL format
+            Logger.w("UrlValidator", "Failed to parse URL: ${e.message}")
             false
         }
     }

android/app/src/main/res/layout/activity_main.xml

@@ -22,6 +22,39 @@
             app:title="@string/app_name"
             app:titleTextAppearance="@style/TextAppearance.Material3.TitleLarge" />
 
+        <!-- 🔄 v1.3.1: Sync Status Banner -->
+        <LinearLayout
+            android:id="@+id/syncStatusBanner"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:orientation="horizontal"
+            android:gravity="center_vertical"
+            android:paddingHorizontal="16dp"
+            android:paddingVertical="8dp"
+            android:background="?attr/colorPrimaryContainer"
+            android:visibility="gone">
+
+            <com.google.android.material.progressindicator.CircularProgressIndicator
+                android:id="@+id/syncProgressIndicator"
+                android:layout_width="24dp"
+                android:layout_height="24dp"
+                android:indeterminate="true"
+                app:indicatorSize="24dp"
+                app:trackThickness="3dp"
+                app:indicatorColor="?attr/colorOnPrimaryContainer" />
+
+            <TextView
+                android:id="@+id/syncStatusText"
+                android:layout_width="0dp"
+                android:layout_height="wrap_content"
+                android:layout_weight="1"
+                android:layout_marginStart="12dp"
+                android:text="@string/sync_status_syncing"
+                android:textAppearance="@style/TextAppearance.Material3.BodyMedium"
+                android:textColor="?attr/colorOnPrimaryContainer" />
+
+        </LinearLayout>
+
     </com.google.android.material.appbar.AppBarLayout>
 
     <!-- SwipeRefreshLayout für Pull-to-Refresh (v1.1.2) -->

android/app/src/main/res/layout/activity_settings.xml

@@ -109,7 +109,7 @@
                         style="@style/Widget.Material3.TextInputLayout.OutlinedBox"
                         app:startIconDrawable="@android:drawable/ic_menu_compass"
                         app:endIconMode="clear_text"
-                        app:helperText="z.B. http://192.168.0.188:8080/webdav"
+                        app:helperText="z.B. http://192.168.0.188:8080/notes"
                         app:helperTextEnabled="true"
                         app:boxCornerRadiusTopStart="12dp"
                         app:boxCornerRadiusTopEnd="12dp"
@@ -387,6 +387,105 @@
 
             </com.google.android.material.card.MaterialCardView>
 
+            <!-- Material 3 Card: Markdown Desktop-Integration (v1.2.0) -->
+            <com.google.android.material.card.MaterialCardView
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:layout_marginBottom="16dp"
+                style="@style/Widget.Material3.CardView.Elevated"
+                app:cardCornerRadius="16dp">
+
+                <LinearLayout
+                    android:layout_width="match_parent"
+                    android:layout_height="wrap_content"
+                    android:orientation="vertical"
+                    android:padding="20dp">
+
+                    <!-- Section Header -->
+                    <TextView
+                        android:layout_width="match_parent"
+                        android:layout_height="wrap_content"
+                        android:text="Markdown Desktop-Integration"
+                        android:textAppearance="@style/TextAppearance.Material3.TitleMedium"
+                        android:layout_marginBottom="12dp" />
+
+                    <!-- Info Card -->
+                    <com.google.android.material.card.MaterialCardView
+                        android:layout_width="match_parent"
+                        android:layout_height="wrap_content"
+                        android:layout_marginBottom="16dp"
+                        app:cardBackgroundColor="?attr/colorPrimaryContainer"
+                        app:cardCornerRadius="12dp"
+                        app:cardElevation="0dp">
+
+                        <TextView
+                            android:layout_width="match_parent"
+                            android:layout_height="wrap_content"
+                            android:padding="16dp"
+                            android:text="ℹ️ Exportiert Notizen zusätzlich als .md Dateien. Mounte WebDAV als Netzlaufwerk um mit VS Code, Typora oder jedem Markdown-Editor zu bearbeiten. JSON-Sync bleibt primäres Format."
+                            android:textAppearance="@style/TextAppearance.Material3.BodySmall"
+                            android:textColor="?attr/colorOnPrimaryContainer"
+                            android:lineSpacingMultiplier="1.3" />
+
+                    </com.google.android.material.card.MaterialCardView>
+
+                    <!-- Markdown Auto-Sync Toggle (fusioniert Export + Auto-Import) -->
+                    <LinearLayout
+                        android:layout_width="match_parent"
+                        android:layout_height="wrap_content"
+                        android:layout_marginBottom="8dp"
+                        android:orientation="horizontal"
+                        android:gravity="center_vertical">
+
+                        <TextView
+                            android:layout_width="0dp"
+                            android:layout_height="wrap_content"
+                            android:layout_weight="1"
+                            android:text="🔄 Markdown Auto-Sync"
+                            android:textAppearance="@style/TextAppearance.Material3.BodyLarge" />
+
+                        <androidx.appcompat.widget.SwitchCompat
+                            android:id="@+id/switchMarkdownAutoSync"
+                            android:layout_width="wrap_content"
+                            android:layout_height="wrap_content"
+                            android:checked="false" />
+
+                    </LinearLayout>
+
+                    <!-- Auto-Sync Info Text -->
+                    <TextView
+                        android:layout_width="match_parent"
+                        android:layout_height="wrap_content"
+                        android:layout_marginBottom="16dp"
+                        android:text="Synchronisiert Notizen automatisch als .md Dateien (Upload + Download bei jedem Sync)"
+                        android:textAppearance="@style/TextAppearance.Material3.BodySmall"
+                        android:textColor="?attr/colorOnSurfaceVariant" />
+
+                    <!-- Manual Sync Info (nur sichtbar wenn Auto-Sync OFF) -->
+                    <TextView
+                        android:id="@+id/textViewManualSyncInfo"
+                        android:layout_width="match_parent"
+                        android:layout_height="wrap_content"
+                        android:layout_marginTop="8dp"
+                        android:layout_marginBottom="8dp"
+                        android:text="Oder synchronisiere Markdown-Dateien manuell:"
+                        android:textAppearance="@style/TextAppearance.Material3.BodyMedium"
+                        android:textColor="?attr/colorOnSurface"
+                        android:visibility="gone" />
+
+                    <!-- Manual Sync Button (nur sichtbar wenn Auto-Sync OFF) -->
+                    <Button
+                        android:id="@+id/buttonManualMarkdownSync"
+                        android:layout_width="match_parent"
+                        android:layout_height="wrap_content"
+                        android:text="Markdown synchronisieren"
+                        android:visibility="gone"
+                        style="@style/Widget.Material3.Button.TonalButton" />
+
+                </LinearLayout>
+
+            </com.google.android.material.card.MaterialCardView>
+
             <!-- Material 3 Card: Backup & Restore -->
             <com.google.android.material.card.MaterialCardView
                 android:layout_width="match_parent"
@@ -409,12 +508,12 @@
                         android:textAppearance="@style/TextAppearance.Material3.TitleMedium"
                         android:layout_marginBottom="12dp" />
 
-                    <!-- Warning Info Card -->
+                    <!-- Info Card (anstatt Warning) -->
                     <com.google.android.material.card.MaterialCardView
                         android:layout_width="match_parent"
                         android:layout_height="wrap_content"
                         android:layout_marginBottom="16dp"
-                        app:cardBackgroundColor="?attr/colorErrorContainer"
+                        app:cardBackgroundColor="?attr/colorPrimaryContainer"
                         app:cardCornerRadius="12dp"
                         app:cardElevation="0dp">
 
@@ -422,19 +521,61 @@
                             android:layout_width="match_parent"
                             android:layout_height="wrap_content"
                             android:padding="16dp"
-                            android:text="@string/backup_restore_warning"
+                            android:text="ℹ️ Bei jeder Wiederherstellung wird automatisch ein Sicherheits-Backup erstellt."
                             android:textAppearance="@style/TextAppearance.Material3.BodySmall"
-                            android:textColor="?attr/colorOnErrorContainer"
+                            android:textColor="?attr/colorOnPrimaryContainer"
                             android:lineSpacingMultiplier="1.3" />
 
                     </com.google.android.material.card.MaterialCardView>
 
-                    <!-- Restore Button -->
+                    <!-- Lokales Backup Sektion -->
+                    <TextView
+                        android:layout_width="match_parent"
+                        android:layout_height="wrap_content"
+                        android:text="Lokales Backup"
+                        android:textAppearance="@style/TextAppearance.Material3.LabelLarge"
+                        android:layout_marginBottom="12dp" />
+
+                    <!-- Backup erstellen Button -->
+                    <Button
+                        android:id="@+id/buttonCreateBackup"
+                        android:layout_width="match_parent"
+                        android:layout_height="wrap_content"
+                        android:text="📥 Backup erstellen"
+                        android:layout_marginBottom="8dp"
+                        style="@style/Widget.Material3.Button.TonalButton" />
+
+                    <!-- Aus Datei wiederherstellen Button -->
+                    <Button
+                        android:id="@+id/buttonRestoreFromFile"
+                        android:layout_width="match_parent"
+                        android:layout_height="wrap_content"
+                        android:text="📤 Aus Datei wiederherstellen"
+                        android:layout_marginBottom="16dp"
+                        style="@style/Widget.Material3.Button.TonalButton" />
+
+                    <!-- Divider -->
+                    <View
+                        android:layout_width="match_parent"
+                        android:layout_height="1dp"
+                        android:background="?attr/colorOutline"
+                        android:layout_marginTop="8dp"
+                        android:layout_marginBottom="16dp" />
+
+                    <!-- Server-Backup Sektion -->
+                    <TextView
+                        android:layout_width="match_parent"
+                        android:layout_height="wrap_content"
+                        android:text="Server-Backup"
+                        android:textAppearance="@style/TextAppearance.Material3.LabelLarge"
+                        android:layout_marginBottom="12dp" />
+
+                    <!-- Vom Server wiederherstellen Button -->
                     <Button
                         android:id="@+id/buttonRestoreFromServer"
                         android:layout_width="match_parent"
                         android:layout_height="wrap_content"
-                        android:text="@string/restore_from_server"
+                        android:text="🔄 Vom Server wiederherstellen"
                         style="@style/Widget.Material3.Button.TonalButton" />
 
                 </LinearLayout>
@@ -608,6 +749,107 @@
 
             </com.google.android.material.card.MaterialCardView>
 
+            <!-- Material 3 Card: Debug Section -->
+            <com.google.android.material.card.MaterialCardView
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:layout_marginBottom="16dp"
+                style="@style/Widget.Material3.CardView.Elevated"
+                app:cardCornerRadius="16dp">
+
+                <LinearLayout
+                    android:layout_width="match_parent"
+                    android:layout_height="wrap_content"
+                    android:orientation="vertical"
+                    android:padding="20dp">
+
+                    <!-- Section Header -->
+                    <TextView
+                        android:layout_width="match_parent"
+                        android:layout_height="wrap_content"
+                        android:text="Debug &amp; Diagnose"
+                        android:textAppearance="@style/TextAppearance.Material3.TitleMedium"
+                        android:layout_marginBottom="16dp" />
+
+                    <!-- File Logging Toggle -->
+                    <com.google.android.material.card.MaterialCardView
+                        android:layout_width="match_parent"
+                        android:layout_height="wrap_content"
+                        android:layout_marginBottom="12dp"
+                        app:cardBackgroundColor="?attr/colorSurfaceVariant"
+                        app:cardCornerRadius="12dp"
+                        app:cardElevation="0dp">
+
+                        <LinearLayout
+                            android:layout_width="match_parent"
+                            android:layout_height="wrap_content"
+                            android:orientation="horizontal"
+                            android:padding="16dp"
+                            android:gravity="center_vertical">
+
+                            <LinearLayout
+                                android:layout_width="0dp"
+                                android:layout_height="wrap_content"
+                                android:layout_weight="1"
+                                android:orientation="vertical">
+
+                                <TextView
+                                    android:layout_width="match_parent"
+                                    android:layout_height="wrap_content"
+                                    android:text="📝 Datei-Logging"
+                                    android:textAppearance="@style/TextAppearance.Material3.LabelLarge"
+                                    android:textColor="?attr/colorPrimary"
+                                    android:layout_marginBottom="4dp" />
+
+                                <TextView
+                                    android:layout_width="match_parent"
+                                    android:layout_height="wrap_content"
+                                    android:text="Sync-Logs in Datei speichern"
+                                    android:textAppearance="@style/TextAppearance.Material3.BodyMedium" />
+
+                            </LinearLayout>
+
+                            <com.google.android.material.materialswitch.MaterialSwitch
+                                android:id="@+id/switchFileLogging"
+                                android:layout_width="wrap_content"
+                                android:layout_height="wrap_content" />
+
+                        </LinearLayout>
+
+                    </com.google.android.material.card.MaterialCardView>
+
+                    <!-- F-Droid Privacy Notice -->
+                    <TextView
+                        android:layout_width="match_parent"
+                        android:layout_height="wrap_content"
+                        android:text="@string/file_logging_privacy_notice"
+                        android:textAppearance="@style/TextAppearance.Material3.BodySmall"
+                        android:textColor="?attr/colorOnSurfaceVariant"
+                        android:layout_marginBottom="16dp"
+                        android:paddingStart="4dp"
+                        android:paddingEnd="4dp" />
+
+                    <!-- Export Logs Button -->
+                    <Button
+                        android:id="@+id/buttonExportLogs"
+                        android:layout_width="match_parent"
+                        android:layout_height="wrap_content"
+                        android:text="📤 Logs exportieren &amp; teilen"
+                        style="@style/Widget.Material3.Button.TonalButton"
+                        android:layout_marginBottom="8dp" />
+
+                    <!-- Clear Logs Button -->
+                    <Button
+                        android:id="@+id/buttonClearLogs"
+                        android:layout_width="match_parent"
+                        android:layout_height="wrap_content"
+                        android:text="🗑️ Logs löschen"
+                        style="@style/Widget.Material3.Button.OutlinedButton" />
+
+                </LinearLayout>
+
+            </com.google.android.material.card.MaterialCardView>
+
         </LinearLayout>
 
     </ScrollView>

android/app/src/main/res/layout/dialog_delete_confirmation.xml

@@ -15,7 +15,7 @@
         android:layout_gravity="center_horizontal"
         android:layout_marginBottom="16dp"
         android:src="@android:drawable/ic_menu_delete"
-        android:tint="?attr/colorError"
+        app:tint="?attr/colorError"
         android:contentDescription="@string/delete" />
 
     <!-- Title -->

android/app/src/main/res/layout/dialog_server_deletion.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:orientation="vertical"
+    android:padding="16dp">
+
+    <CheckBox
+        android:id="@+id/checkboxAlwaysDeleteFromServer"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:text="Diese Entscheidung merken"
+        android:textAppearance="@style/TextAppearance.Material3.BodyMedium" />
+
+</LinearLayout>

android/app/src/main/res/layout/item_note.xml

@@ -64,7 +64,7 @@
                 android:layout_height="18dp"
                 android:layout_gravity="center_vertical"
                 android:src="@android:drawable/ic_popup_sync"
-                android:tint="?attr/colorPrimary"
+                app:tint="?attr/colorPrimary"
                 android:contentDescription="@string/sync_status" />
 
         </LinearLayout>

android/app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml

@@ -1,5 +1,5 @@
-<?xml version="1.0" encoding="utf-8"?>
 <adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
-    <background android:drawable="@mipmap/ic_launcher_background"/>
+  <background android:drawable="@color/ic_launcher_background"/>
   <foreground android:drawable="@mipmap/ic_launcher_foreground"/>
+  <monochrome android:drawable="@mipmap/ic_launcher_monochrome"/>
 </adaptive-icon>

android/app/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml

@@ -1,5 +1,5 @@
-<?xml version="1.0" encoding="utf-8"?>
 <adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
-    <background android:drawable="@mipmap/ic_launcher_background"/>
+  <background android:drawable="@color/ic_launcher_background"/>
   <foreground android:drawable="@mipmap/ic_launcher_foreground"/>
+  <monochrome android:drawable="@mipmap/ic_launcher_monochrome"/>
 </adaptive-icon>

android/app/src/main/res/values/colors.xml

@@ -4,6 +4,9 @@
     <color name="black">#FF000000</color>
     <color name="white">#FFFFFFFF</color>
     
+    <!-- Adaptive Icon Background -->
+    <color name="ic_launcher_background">#f9e9c8</color>
+    
     <!-- Material 3 Light Theme Colors -->
     <color name="md_theme_light_primary">#6750A4</color>
     <color name="md_theme_light_onPrimary">#FFFFFF</color>

android/app/src/main/res/values/strings.xml

@@ -57,4 +57,13 @@
     <string name="restore_progress">Stelle Notizen wieder her…</string>
     <string name="restore_success">✓ %d Notizen wiederhergestellt</string>
     <string name="restore_error">Fehler: %s</string>
+    
+    <!-- Sync Status Banner (v1.3.1) -->
+    <string name="sync_status_syncing">Synchronisiere…</string>
+    <string name="sync_status_completed">Synchronisierung abgeschlossen</string>
+    <string name="sync_status_error">Synchronisierung fehlgeschlagen</string>
+    <string name="sync_already_running">Synchronisierung läuft bereits</string>
+    
+    <!-- Debug/Logging Section (v1.3.2) -->
+    <string name="file_logging_privacy_notice">ℹ️ Datenschutz: Logs werden nur lokal auf deinem Gerät gespeichert und niemals an externe Server gesendet. Die Logs enthalten Sync-Aktivitäten zur Fehlerdiagnose. Du kannst sie jederzeit löschen oder exportieren.</string>
 </resources>

android/build.gradle.kts

@@ -2,4 +2,6 @@
 plugins {
     alias(libs.plugins.android.application) apply false
     alias(libs.plugins.kotlin.android) apply false
+    alias(libs.plugins.ktlint) apply false
+    alias(libs.plugins.detekt) apply false
 }

android/config/detekt/detekt.yml

@@ -0,0 +1,136 @@
+# ⚡ v1.3.1: detekt Configuration
+# Pragmatic rules for simple-notes-sync
+
+build:
+  maxIssues: 100  # Allow existing issues for v1.3.1 release, fix in v1.4.0
+  excludeCorrectable: false
+
+config:
+  validation: true
+  warningsAsErrors: false
+
+comments:
+  CommentOverPrivateProperty:
+    active: false
+  UndocumentedPublicClass:
+    active: false
+  UndocumentedPublicFunction:
+    active: false
+
+complexity:
+  ComplexCondition:
+    active: true
+    threshold: 5
+  CyclomaticComplexMethod:
+    active: true
+    threshold: 15
+    ignoreSingleWhenExpression: true
+  LargeClass:
+    active: true
+    threshold: 600  # Increased for WebDavSyncService
+  LongMethod:
+    active: true
+    threshold: 80  # Increased for sync methods
+  LongParameterList:
+    active: true
+    functionThreshold: 6
+    constructorThreshold: 7
+  NestedBlockDepth:
+    active: true
+    threshold: 5
+  TooManyFunctions:
+    active: true
+    thresholdInFiles: 25
+    thresholdInClasses: 25
+    thresholdInInterfaces: 20
+    thresholdInObjects: 20
+    thresholdInEnums: 10
+
+empty-blocks:
+  EmptyCatchBlock:
+    active: true
+    allowedExceptionNameRegex: "_|(ignore|expected).*"
+  EmptyFunctionBlock:
+    active: true
+    ignoreOverridden: true
+
+exceptions:
+  SwallowedException:
+    active: true
+    ignoredExceptionTypes:
+      - "InterruptedException"
+      - "MalformedURLException"
+      - "NumberFormatException"
+      - "ParseException"
+  TooGenericExceptionCaught:
+    active: true
+    exceptionNames:
+      - "Error"
+      - "Throwable"
+    allowedExceptionNameRegex: "_|(ignore|expected).*"
+
+naming:
+  FunctionNaming:
+    active: true
+    functionPattern: "[a-zA-Z][a-zA-Z0-9]*"
+  VariableNaming:
+    active: true
+    variablePattern: "[a-z][A-Za-z0-9]*"
+  PackageNaming:
+    active: true
+    packagePattern: "[a-z]+(\\.[a-z][A-Za-z0-9]*)*"
+
+performance:
+  SpreadOperator:
+    active: false  # Spread operator is fine in most cases
+
+potential-bugs:
+  CastToNullableType:
+    active: true
+  EqualsWithHashCodeExist:
+    active: true
+  UnconditionalJumpStatementInLoop:
+    active: true
+
+style:
+  ForbiddenComment:
+    active: true
+    comments:
+      - "FIXME:"
+      - "STOPSHIP:"
+    allowedPatterns: ""
+  MagicNumber:
+    active: true
+    ignoreNumbers:
+      - "-1"
+      - "0"
+      - "1"
+      - "2"
+      - "100"
+      - "1000"
+    ignoreHashCodeFunction: true
+    ignorePropertyDeclaration: true
+    ignoreLocalVariableDeclaration: true
+    ignoreAnnotation: true
+    ignoreEnums: true
+    ignoreRanges: true
+    ignoreExtensionFunctions: true
+  MaxLineLength:
+    active: true
+    maxLineLength: 120
+    excludePackageStatements: true
+    excludeImportStatements: true
+  ReturnCount:
+    active: true
+    max: 4
+    excludedFunctions: []
+    excludeLabeled: true
+    excludeReturnFromLambda: true
+    excludeGuardClauses: true
+  UnusedImports:
+    active: true
+  UnusedPrivateMember:
+    active: true
+    allowedNames: "_.*"
+  WildcardImport:
+    active: false  # Allow wildcard imports

android/gradle/libs.versions.toml

@@ -9,6 +9,8 @@ appcompat = "1.6.1"
 material = "1.10.0"
 activity = "1.8.0"
 constraintlayout = "2.1.4"
+ktlint = "12.1.0"
+detekt = "1.23.4"
 
 [libraries]
 androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" }
@@ -23,4 +25,6 @@ androidx-constraintlayout = { group = "androidx.constraintlayout", name = "const
 [plugins]
 android-application = { id = "com.android.application", version.ref = "agp" }
 kotlin-android = { id = "org.jetbrains.kotlin.android", version.ref = "kotlin" }
+ktlint = { id = "org.jlleitschuh.gradle.ktlint", version.ref = "ktlint" }
+detekt = { id = "io.gitlab.arturbosch.detekt", version.ref = "detekt" }
 

docs/BACKUP.en.md

@@ -0,0 +1,324 @@
+# Backup & Restore 💾
+
+**🌍 Languages:** [Deutsch](BACKUP.md) · **English**
+
+> Secure your notes locally - independent from the server
+
+---
+
+## 📋 Overview
+
+The backup system works **completely offline** and independent from the WebDAV server. Perfect for:
+- 📥 Regular backups
+- 📤 Migration to new server
+- 🔄 Recovery after data loss
+- 💾 Archiving old notes
+
+---
+
+## 📥 Create Backup
+
+### Step-by-Step
+
+1. **Open settings** (⚙️ icon top right)
+2. **Find "Backup & Restore"** section
+3. **Tap "📥 Create backup"**
+4. **Choose location:**
+   - 📁 Downloads
+   - 💳 SD card
+   - ☁️ Cloud folder (Nextcloud, Google Drive, etc.)
+   - 📧 Email as attachment
+5. **Done!** Backup file is saved
+
+### File Format
+
+**Filename:** `simplenotes_backup_YYYY-MM-DD_HHmmss.json`
+
+**Example:** `simplenotes_backup_2026-01-05_143022.json`
+
+**Content:**
+```json
+{
+  "version": "1.2.1",
+  "exported_at": "2026-01-05T14:30:22Z",
+  "notes_count": 42,
+  "notes": [
+    {
+      "id": "abc-123-def",
+      "title": "Shopping List",
+      "content": "Milk\nBread\nCheese",
+      "createdAt": 1704467422000,
+      "updatedAt": 1704467422000
+    }
+  ]
+}
+```
+
+**Format details:**
+- ✅ Human-readable (formatted JSON)
+- ✅ All data included (title, content, IDs, timestamps)
+- ✅ Version info for compatibility
+- ✅ Note count for validation
+
+---
+
+## 📤 Restore Backup
+
+### 3 Restore Modes
+
+#### 1. Merge ⭐ _Recommended_
+
+**What happens:**
+- ✅ New notes from backup are added
+- ✅ Existing notes remain unchanged
+- ✅ No data loss
+
+**When to use:**
+- Import backup from another device
+- Recover old notes
+- Restore accidentally deleted notes
+
+**Example:**
+```
+App:    [Note A, Note B, Note C]
+Backup: [Note A, Note D, Note E]
+Result: [Note A, Note B, Note C, Note D, Note E]
+```
+
+#### 2. Replace
+
+**What happens:**
+- ❌ ALL existing notes are deleted
+- ✅ Backup notes are imported
+- ⚠️ Irreversible (except through auto-backup)
+
+**When to use:**
+- Server migration (complete restart)
+- Return to old backup state
+- App reinstallation
+
+**Example:**
+```
+App:    [Note A, Note B, Note C]
+Backup: [Note X, Note Y]
+Result: [Note X, Note Y]
+```
+
+**⚠️ Warning:** Automatic safety backup is created!
+
+#### 3. Overwrite Duplicates
+
+**What happens:**
+- ✅ New notes from backup are added
+- 🔄 On ID conflicts, backup wins
+- ✅ Other notes remain unchanged
+
+**When to use:**
+- Backup is newer than app data
+- Import desktop changes
+- Conflict resolution
+
+**Example:**
+```
+App:    [Note A (v1), Note B, Note C]
+Backup: [Note A (v2), Note D]
+Result: [Note A (v2), Note B, Note C, Note D]
+```
+
+### Restore Process
+
+1. **Settings** → **"📤 Restore from file"**
+2. **Select backup file** (`.json`)
+3. **Choose mode:**
+   - 🔵 Merge _(Default)_
+   - 🟡 Overwrite duplicates
+   - 🔴 Replace _(Caution!)_
+4. **Confirm** - Automatic safety backup is created
+5. **Wait** - Import runs
+6. **Done!** - Success message with number of imported notes
+
+---
+
+## 🛡️ Automatic Safety Backup
+
+**Before every restore:**
+- ✅ Automatic backup is created
+- 📁 Saved in: `Android/data/dev.dettmer.simplenotes/files/`
+- 🏷️ Filename: `auto_backup_before_restore_YYYY-MM-DD_HHmmss.json`
+- ⏱️ Timestamp: Right before restore
+
+**Why?**
+- Protection against accidental "Replace"
+- Ability to undo
+- Double security
+
+**Access via file manager:**
+```
+/Android/data/dev.dettmer.simplenotes/files/auto_backup_before_restore_*.json
+```
+
+---
+
+## 💡 Best Practices
+
+### Backup Strategy
+
+#### Regular Backups
+```
+Daily:   ❌ Too often (server sync is enough)
+Weekly:  ✅ Recommended for important notes
+Monthly: ✅ Archiving
+Before updates: ✅ Safety
+```
+
+#### 3-2-1 Rule
+1. **3 copies** - Original + 2 backups
+2. **2 media** - e.g., SD card + cloud
+3. **1 offsite** - e.g., cloud storage
+
+### Backup Locations
+
+**Local (fast):**
+- 📱 Internal storage / Downloads
+- 💳 SD card
+- 🖥️ PC (via USB)
+
+**Cloud (secure):**
+- ☁️ Nextcloud (self-hosted)
+- 📧 Email to yourself
+- 🗄️ Syncthing (sync between devices)
+
+**⚠️ Avoid:**
+- ❌ Google Drive / Dropbox (privacy)
+- ❌ Only one copy
+- ❌ Only on server (if server fails)
+
+---
+
+## 🔧 Advanced Usage
+
+### Edit Backup File
+
+The `.json` file can be edited with any text editor:
+
+1. **Open with:** VS Code, Notepad++, nano
+2. **Add/remove notes**
+3. **Change title/content**
+4. **Adjust IDs** (for migration)
+5. **Save** and import to app
+
+**⚠️ Important:**
+- Keep valid JSON format
+- IDs must be unique (UUIDs)
+- Timestamps in milliseconds (Unix Epoch)
+
+### Bulk Import
+
+Merge multiple backups:
+
+1. Import backup 1 (Mode: Merge)
+2. Import backup 2 (Mode: Merge)
+3. Import backup 3 (Mode: Merge)
+4. Result: All notes combined
+
+### Server Migration
+
+Step-by-step:
+
+1. **Create backup** on old server
+2. **Set up new server** (see [QUICKSTART.en.md](QUICKSTART.en.md))
+3. **Change server URL** in app settings
+4. **Restore backup** (Mode: Replace)
+5. **Test sync** - All notes on new server
+
+---
+
+## ❌ Troubleshooting
+
+### "Invalid backup file"
+
+**Causes:**
+- Corrupt JSON file
+- Wrong file extension (must be `.json`)
+- Incompatible app version
+
+**Solution:**
+1. Check JSON file with validator (e.g., jsonlint.com)
+2. Verify file extension
+3. Create backup with current app version
+
+### "No permission to save"
+
+**Causes:**
+- Storage permission missing
+- Write-protected folder
+
+**Solution:**
+1. Android: Settings → Apps → Simple Notes → Permissions
+2. Activate "Storage"
+3. Choose different location
+
+### "Import failed"
+
+**Causes:**
+- Not enough storage space
+- Corrupt backup file
+- App crash during import
+
+**Solution:**
+1. Free up storage space
+2. Create new backup file
+3. Restart app and try again
+
+---
+
+## 🔒 Security & Privacy
+
+### Data Protection
+- ✅ **Locally stored** - No cloud upload without your action
+- ✅ **No encryption** - Plain text format for readability
+- ⚠️ **Sensitive data?** - Encrypt backup file yourself (e.g., 7-Zip with password)
+
+### Recommendations
+- 🔐 Store backup files in encrypted container
+- 🗑️ Regularly delete old backups
+- 📧 Don't send via unencrypted email
+- ☁️ Use self-hosted cloud (Nextcloud)
+
+---
+
+## 📊 Technical Details
+
+### Format Specification
+
+**JSON structure:**
+```json
+{
+  "version": "string",        // App version at export
+  "exported_at": "ISO8601",   // Export timestamp
+  "notes_count": number,      // Number of notes
+  "notes": [
+    {
+      "id": "UUID",           // Unique ID
+      "title": "string",      // Note title
+      "content": "string",    // Note content
+      "createdAt": number,    // Unix timestamp (ms)
+      "updatedAt": number     // Unix timestamp (ms)
+    }
+  ]
+}
+```
+
+### Compatibility
+- ✅ v1.2.0+ - Fully compatible
+- ⚠️ v1.1.x - Basic functions (without auto-backup)
+- ❌ v1.0.x - Not supported
+
+---
+
+**📚 See also:**
+- [QUICKSTART.en.md](../QUICKSTART.en.md) - App installation and setup
+- [FEATURES.en.md](FEATURES.en.md) - Complete feature list
+- [DESKTOP.en.md](DESKTOP.en.md) - Desktop integration with Markdown
+
+**Last update:** v1.2.1 (2026-01-05)

docs/BACKUP.md

@@ -0,0 +1,324 @@
+# Backup & Wiederherstellung 💾
+
+**🌍 Languages:** **Deutsch** · [English](BACKUP.en.md)
+
+> Sichere deine Notizen lokal - unabhängig vom Server
+
+---
+
+## 📋 Übersicht
+
+Das Backup-System funktioniert **komplett offline** und unabhängig vom WebDAV-Server. Perfekt für:
+- 📥 Regelmäßige Sicherungen
+- 📤 Migration zu neuem Server
+- 🔄 Wiederherstellung nach Datenverlust
+- 💾 Archivierung alter Notizen
+
+---
+
+## 📥 Backup erstellen
+
+### Schritt-für-Schritt
+
+1. **Einstellungen öffnen** (⚙️ Icon oben rechts)
+2. **"Backup & Wiederherstellung"** Section finden
+3. **"📥 Backup erstellen"** antippen
+4. **Speicherort wählen:**
+   - 📁 Downloads
+   - 💳 SD-Karte
+   - ☁️ Cloud-Ordner (Nextcloud, Google Drive, etc.)
+   - 📧 E-Mail als Anhang
+5. **Fertig!** Backup-Datei ist gespeichert
+
+### Dateiformat
+
+**Dateiname:** `simplenotes_backup_YYYY-MM-DD_HHmmss.json`
+
+**Beispiel:** `simplenotes_backup_2026-01-05_143022.json`
+
+**Inhalt:**
+```json
+{
+  "version": "1.2.1",
+  "exported_at": "2026-01-05T14:30:22Z",
+  "notes_count": 42,
+  "notes": [
+    {
+      "id": "abc-123-def",
+      "title": "Einkaufsliste",
+      "content": "Milch\nBrot\nKäse",
+      "createdAt": 1704467422000,
+      "updatedAt": 1704467422000
+    }
+  ]
+}
+```
+
+**Format-Details:**
+- ✅ Menschenlesbar (formatiertes JSON)
+- ✅ Alle Daten inklusive (Titel, Inhalt, IDs, Timestamps)
+- ✅ Versions-Info für Kompatibilität
+- ✅ Anzahl der Notizen für Validierung
+
+---
+
+## 📤 Backup wiederherstellen
+
+### 3 Wiederherstellungs-Modi
+
+#### 1. Zusammenführen (Merge) ⭐ _Empfohlen_
+
+**Was passiert:**
+- ✅ Neue Notizen aus Backup werden hinzugefügt
+- ✅ Bestehende Notizen bleiben unverändert
+- ✅ Keine Datenverluste
+
+**Wann nutzen:**
+- Backup von anderem Gerät einspielen
+- Alte Notizen zurückholen
+- Versehentlich gelöschte Notizen wiederherstellen
+
+**Beispiel:**
+```
+App:    [Notiz A, Notiz B, Notiz C]
+Backup: [Notiz A, Notiz D, Notiz E]
+Ergebnis: [Notiz A, Notiz B, Notiz C, Notiz D, Notiz E]
+```
+
+#### 2. Ersetzen (Replace)
+
+**Was passiert:**
+- ❌ ALLE bestehenden Notizen werden gelöscht
+- ✅ Backup-Notizen werden importiert
+- ⚠️ Unwiderruflich (außer durch Auto-Backup)
+
+**Wann nutzen:**
+- Server-Wechsel (kompletter Neustart)
+- Zurück zu altem Backup-Stand
+- App-Neuinstallation
+
+**Beispiel:**
+```
+App:    [Notiz A, Notiz B, Notiz C]
+Backup: [Notiz X, Notiz Y]
+Ergebnis: [Notiz X, Notiz Y]
+```
+
+**⚠️ Warnung:** Automatisches Sicherheits-Backup wird erstellt!
+
+#### 3. Duplikate überschreiben (Overwrite)
+
+**Was passiert:**
+- ✅ Neue Notizen aus Backup werden hinzugefügt
+- 🔄 Bei ID-Konflikten gewinnt das Backup
+- ✅ Andere Notizen bleiben unverändert
+
+**Wann nutzen:**
+- Backup ist neuer als App-Daten
+- Desktop-Änderungen einspielen
+- Konflikt-Auflösung
+
+**Beispiel:**
+```
+App:    [Notiz A (v1), Notiz B, Notiz C]
+Backup: [Notiz A (v2), Notiz D]
+Ergebnis: [Notiz A (v2), Notiz B, Notiz C, Notiz D]
+```
+
+### Wiederherstellungs-Prozess
+
+1. **Einstellungen** → **"📤 Aus Datei wiederherstellen"**
+2. **Backup-Datei auswählen** (`.json`)
+3. **Modus wählen:**
+   - 🔵 Zusammenführen _(Standard)_
+   - 🟡 Duplikate überschreiben
+   - 🔴 Ersetzen _(Vorsicht!)_
+4. **Bestätigen** - Automatisches Sicherheits-Backup wird erstellt
+5. **Warten** - Import läuft
+6. **Fertig!** - Erfolgsmeldung mit Anzahl importierter Notizen
+
+---
+
+## 🛡️ Automatisches Sicherheits-Backup
+
+**Vor jeder Wiederherstellung:**
+- ✅ Automatisches Backup wird erstellt
+- 📁 Gespeichert in: `Android/data/dev.dettmer.simplenotes/files/`
+- 🏷️ Dateiname: `auto_backup_before_restore_YYYY-MM-DD_HHmmss.json`
+- ⏱️ Zeitstempel: Direkt vor Wiederherstellung
+
+**Warum?**
+- Schutz vor versehentlichem "Ersetzen"
+- Möglichkeit zum Rückgängigmachen
+- Doppelte Sicherheit
+
+**Zugriff via Dateimanager:**
+```
+/Android/data/dev.dettmer.simplenotes/files/auto_backup_before_restore_*.json
+```
+
+---
+
+## 💡 Best Practices
+
+### Backup-Strategie
+
+#### Regelmäßige Backups
+```
+Täglich:   ❌ Zu oft (Server-Sync reicht)
+Wöchentlich: ✅ Empfohlen für wichtige Notizen
+Monatlich:  ✅ Archivierung
+Vor Updates: ✅ Sicherheit
+```
+
+#### 3-2-1 Regel
+1. **3 Kopien** - Original + 2 Backups
+2. **2 Medien** - z.B. SD-Karte + Cloud
+3. **1 Offsite** - z.B. Cloud-Speicher
+
+### Backup-Speicherorte
+
+**Lokal (schnell):**
+- 📱 Internal Storage / Downloads
+- 💳 SD-Karte
+- 🖥️ PC (via USB)
+
+**Cloud (sicher):**
+- ☁️ Nextcloud (Self-Hosted)
+- 📧 E-Mail an sich selbst
+- 🗄️ Syncthing (Sync zwischen Geräten)
+
+**⚠️ Vermeiden:**
+- ❌ Google Drive / Dropbox (Privacy)
+- ❌ Nur eine Kopie
+- ❌ Nur auf Server (wenn Server ausfällt)
+
+---
+
+## 🔧 Erweiterte Nutzung
+
+### Backup-Datei bearbeiten
+
+Die `.json` Datei kann mit jedem Texteditor bearbeitet werden:
+
+1. **Öffnen mit:** VS Code, Notepad++, nano
+2. **Notizen hinzufügen/entfernen**
+3. **Titel/Inhalt ändern**
+4. **IDs anpassen** (für Migration)
+5. **Speichern** und in App importieren
+
+**⚠️ Wichtig:**
+- Valides JSON-Format behalten
+- IDs müssen eindeutig sein (UUIDs)
+- Timestamps in Millisekunden (Unix Epoch)
+
+### Bulk-Import
+
+Mehrere Backups zusammenführen:
+
+1. Backup 1 importieren (Modus: Zusammenführen)
+2. Backup 2 importieren (Modus: Zusammenführen)
+3. Backup 3 importieren (Modus: Zusammenführen)
+4. Ergebnis: Alle Notizen vereint
+
+### Server-Migration
+
+Schritt-für-Schritt:
+
+1. **Backup erstellen** auf altem Server
+2. **Neuen Server einrichten** (siehe [QUICKSTART.md](QUICKSTART.md))
+3. **Server-URL ändern** in App-Einstellungen
+4. **Backup wiederherstellen** (Modus: Ersetzen)
+5. **Sync testen** - Alle Notizen auf neuem Server
+
+---
+
+## ❌ Fehlerbehebung
+
+### "Backup-Datei ungültig"
+
+**Ursachen:**
+- Korrupte JSON-Datei
+- Falsche Datei-Endung (muss `.json` sein)
+- Inkompatible App-Version
+
+**Lösung:**
+1. JSON-Datei mit Validator prüfen (z.B. jsonlint.com)
+2. Dateiendung überprüfen
+3. Backup mit aktueller App-Version erstellen
+
+### "Keine Berechtigung zum Speichern"
+
+**Ursachen:**
+- Speicher-Berechtigung fehlt
+- Schreibgeschützter Ordner
+
+**Lösung:**
+1. Android: Einstellungen → Apps → Simple Notes → Berechtigungen
+2. "Speicher" aktivieren
+3. Anderen Speicherort wählen
+
+### "Import fehlgeschlagen"
+
+**Ursachen:**
+- Zu wenig Speicherplatz
+- Korrupte Backup-Datei
+- App-Crash während Import
+
+**Lösung:**
+1. Speicherplatz freigeben
+2. Backup-Datei neu erstellen
+3. App neu starten und erneut importieren
+
+---
+
+## 🔒 Sicherheit & Privacy
+
+### Daten-Schutz
+- ✅ **Lokal gespeichert** - Kein Cloud-Upload ohne deine Aktion
+- ✅ **Keine Verschlüsselung** - Klartextformat für Lesbarkeit
+- ⚠️ **Sensible Daten?** - Backup-Datei selbst verschlüsseln (z.B. 7-Zip mit Passwort)
+
+### Empfehlungen
+- 🔐 Backup-Dateien in verschlüsseltem Container speichern
+- 🗑️ Alte Backups regelmäßig löschen
+- 📧 Nicht per unverschlüsselter E-Mail versenden
+- ☁️ Self-Hosted Cloud nutzen (Nextcloud)
+
+---
+
+## 📊 Technische Details
+
+### Format-Spezifikation
+
+**JSON-Struktur:**
+```json
+{
+  "version": "string",        // App-Version beim Export
+  "exported_at": "ISO8601",   // Zeitstempel des Exports
+  "notes_count": number,      // Anzahl der Notizen
+  "notes": [
+    {
+      "id": "UUID",           // Eindeutige ID
+      "title": "string",      // Notiz-Titel
+      "content": "string",    // Notiz-Inhalt
+      "createdAt": number,    // Unix Timestamp (ms)
+      "updatedAt": number     // Unix Timestamp (ms)
+    }
+  ]
+}
+```
+
+### Kompatibilität
+- ✅ v1.2.0+ - Vollständig kompatibel
+- ⚠️ v1.1.x - Grundfunktionen (ohne Auto-Backup)
+- ❌ v1.0.x - Nicht unterstützt
+
+---
+
+**📚 Siehe auch:**
+- [QUICKSTART.md](../QUICKSTART.md) - App-Installation und Einrichtung
+- [FEATURES.md](FEATURES.md) - Vollständige Feature-Liste
+- [DESKTOP.md](DESKTOP.md) - Desktop-Integration mit Markdown
+
+**Letzte Aktualisierung:** v1.2.1 (2026-01-05)

docs/DESKTOP.en.md

@@ -0,0 +1,505 @@
+# Desktop Integration 🖥️
+
+**🌍 Languages:** [Deutsch](DESKTOP.md) · **English**
+
+> Edit your notes with any Markdown editor on desktop
+
+---
+
+## 📋 Overview
+
+Desktop integration allows you to edit notes on PC/Mac:
+- 📝 Any Markdown editor works
+- 🔄 Automatic synchronization via WebDAV
+- 💾 Dual-format: JSON (master) + Markdown (mirror)
+- ⚡ Last-Write-Wins conflict resolution
+
+---
+
+## 🎯 Why Markdown?
+
+### Dual-Format Architecture
+
+```
+┌─────────────────────────────────────┐
+│         Android App                 │
+│                                     │
+│  ┌──────────┐      ┌─────────────┐ │
+│  │   JSON   │ ──→  │  Markdown   │ │
+│  │ (Master) │      │  (Mirror)   │ │
+│  └──────────┘      └─────────────┘ │
+└────────┬────────────────┬───────────┘
+         │                │
+         ↓                ↓
+    WebDAV Server
+         │                │
+    ┌────┴────┐      ┌────┴──────┐
+    │ /notes/ │      │ /notes-md/│
+    │ *.json  │      │ *.md      │
+    └─────────┘      └───────────┘
+         ↑                ↑
+         │                │
+    ┌────┴────────────────┴───────────┐
+    │      Desktop Editor              │
+    │  (VS Code, Typora, etc.)         │
+    └──────────────────────────────────┘
+```
+
+### Advantages
+
+**JSON (Master):**
+- ✅ Reliable and fast
+- ✅ Structured data (IDs, timestamps)
+- ✅ Primary sync mechanism
+- ✅ Always active
+
+**Markdown (Mirror):**
+- ✅ Human-readable
+- ✅ Desktop editor compatible
+- ✅ Syntax highlighting
+- ✅ Optionally activatable
+
+---
+
+## 🚀 Quick Start
+
+### 1. First Synchronization
+
+**Important:** Perform a sync FIRST before activating desktop integration!
+
+1. **Set up app** (see [QUICKSTART.en.md](QUICKSTART.en.md))
+2. **Test server connection**
+3. **Create first note**
+4. **Synchronize** (pull-to-refresh or auto-sync)
+5. ✅ Server automatically creates `/notes/` and `/notes-md/` folders
+
+### 2. Activate Desktop Integration
+
+1. **Settings** → **Desktop Integration**
+2. **Toggle ON**
+3. **Initial export starts** - Shows progress (X/Y)
+4. ✅ All existing notes are exported as `.md`
+
+### 3. Mount WebDAV as Network Drive
+
+#### Windows
+
+```
+1. Open Explorer
+2. Right-click on "This PC"
+3. "Map network drive"
+4. Enter URL: http://YOUR-SERVER:8080/notes-md/
+5. Username: noteuser
+6. Password: (your WebDAV password)
+7. Drive letter: Z:\ (or any)
+8. Done!
+```
+
+**Access:** `Z:\` in Explorer
+
+#### macOS
+
+```
+1. Open Finder
+2. Menu "Go" → "Connect to Server" (⌘K)
+3. Server address: http://YOUR-SERVER:8080/notes-md/
+4. Connect
+5. Username: noteuser
+6. Password: (your WebDAV password)
+7. Done!
+```
+
+**Access:** Finder → Network → notes-md
+
+#### Linux (GNOME)
+
+```
+1. Open Files / Nautilus
+2. "Other Locations"
+3. "Connect to Server"
+4. Server address: dav://YOUR-SERVER:8080/notes-md/
+5. Username: noteuser
+6. Password: (your WebDAV password)
+7. Done!
+```
+
+**Access:** `/run/user/1000/gvfs/dav:host=...`
+
+#### Linux (davfs2 - permanent)
+
+```bash
+# Installation
+sudo apt install davfs2
+
+# Create mount point
+sudo mkdir -p /mnt/notes-md
+
+# Mount once
+sudo mount -t davfs http://YOUR-SERVER:8080/notes-md/ /mnt/notes-md
+
+# Permanent in /etc/fstab
+echo "http://YOUR-SERVER:8080/notes-md/ /mnt/notes-md davfs rw,user,noauto 0 0" | sudo tee -a /etc/fstab
+```
+
+**Access:** `/mnt/notes-md/`
+
+---
+
+## 📝 Markdown Editors
+
+### Recommended Editors
+
+#### 1. VS Code ⭐ _Recommended_
+
+**Advantages:**
+- ✅ Free & open source
+- ✅ Markdown preview (Ctrl+Shift+V)
+- ✅ Syntax highlighting
+- ✅ Git integration
+- ✅ Extensions (spell check, etc.)
+
+**Setup:**
+```
+1. Install VS Code
+2. Mount WebDAV drive
+3. Open folder: Z:\notes-md\ (Windows) or /mnt/notes-md (Linux)
+4. Done! Edit Markdown files
+```
+
+**Extensions (optional):**
+- `Markdown All in One` - Shortcuts & preview
+- `Markdown Preview Enhanced` - Better preview
+- `Code Spell Checker` - Spell checking
+
+#### 2. Typora
+
+**Advantages:**
+- ✅ WYSIWYG Markdown editor
+- ✅ Minimalist design
+- ✅ Live preview
+- ⚠️ Paid (~15€)
+
+**Setup:**
+```
+1. Install Typora
+2. Mount WebDAV
+3. Open folder in Typora
+4. Edit notes
+```
+
+#### 3. Notepad++
+
+**Advantages:**
+- ✅ Lightweight
+- ✅ Fast
+- ✅ Syntax highlighting
+- ⚠️ No Markdown preview
+
+**Setup:**
+```
+1. Install Notepad++
+2. Mount WebDAV
+3. Open files directly
+```
+
+#### 4. Obsidian
+
+**Advantages:**
+- ✅ Second brain philosophy
+- ✅ Graph view for links
+- ✅ Many plugins
+- ⚠️ Sync conflicts possible (2 masters)
+
+**Setup:**
+```
+1. Install Obsidian
+2. Open WebDAV as vault
+3. Caution: Obsidian creates own metadata!
+```
+
+**⚠️ Not recommended:** Can alter frontmatter
+
+---
+
+## 📄 Markdown File Format
+
+### Structure
+
+Each note is exported as `.md` file with YAML frontmatter:
+
+```markdown
+---
+id: abc-123-def-456
+created: 2026-01-05T14:30:22Z
+updated: 2026-01-05T14:30:22Z
+tags: []
+---
+
+# Note Title
+
+Note content here...
+```
+
+### Frontmatter Fields
+
+| Field | Type | Description | Required |
+|-------|------|-------------|----------|
+| `id` | UUID | Unique note ID | ✅ Yes |
+| `created` | ISO8601 | Creation date | ✅ Yes |
+| `updated` | ISO8601 | Modification date | ✅ Yes |
+| `tags` | Array | Tags (future) | ❌ No |
+
+### Filenames
+
+**Sanitization rules:**
+```
+Title: "My Shopping List 🛒"
+→ Filename: "My_Shopping_List.md"
+
+Removed:
+- Emojis: 🛒 → removed
+- Special chars: / \ : * ? " < > | → removed
+- Multiple spaces → single space
+- Spaces → underscore _
+```
+
+**Examples:**
+```
+"Meeting Notes 2026" → "Meeting_Notes_2026.md"
+"To-Do: Project" → "To-Do_Project.md"
+"Vacation ☀️" → "Vacation.md"
+```
+
+---
+
+## 🔄 Synchronization
+
+### Workflow: Android → Desktop
+
+1. **Create/edit note in app**
+2. **Run sync** (auto or manual)
+3. **JSON is uploaded** (`/notes/abc-123.json`)
+4. **Markdown is exported** (`/notes-md/Note_Title.md`) _(only if Desktop Integration ON)_
+5. **Desktop editor shows changes** (after refresh)
+
+### Workflow: Desktop → Android
+
+1. **Edit Markdown file** (in mounted folder)
+2. **Save** - File is immediately on server
+3. **In app: Run Markdown import**
+   - Settings → "Import Markdown Changes"
+   - Or: Auto-import on every sync (future)
+4. **App adopts changes** (if desktop version is newer)
+
+### Conflict Resolution: Last-Write-Wins
+
+**Rule:** Newest version (by `updated` timestamp) wins
+
+**Example:**
+```
+App version:     updated: 2026-01-05 14:00
+Desktop version: updated: 2026-01-05 14:30
+→ Desktop wins (newer timestamp)
+```
+
+**Automatic:**
+- ✅ On Markdown import
+- ✅ On JSON sync
+- ⚠️ No merge conflicts - only complete overwrite
+
+---
+
+## ⚙️ Settings
+
+### Desktop Integration Toggle
+
+**Settings → Desktop Integration**
+
+**ON (activated):**
+- ✅ New notes → automatically exported as `.md`
+- ✅ Updated notes → `.md` update
+- ✅ Deleted notes → `.md` remains (future: also delete)
+
+**OFF (deactivated):**
+- ❌ No Markdown export
+- ✅ JSON sync continues normally
+- ✅ Existing `.md` files remain
+
+### Initial Export
+
+**What happens on activation:**
+1. All existing notes are scanned
+2. Progress dialog shows progress (e.g., "23/42")
+3. Each note is exported as `.md`
+4. On errors: Individual note is skipped
+5. Success message with number of exported notes
+
+**Time:** ~1-2 seconds per 50 notes
+
+---
+
+## 🛠️ Advanced Usage
+
+### Manual Markdown Creation
+
+You can create `.md` files manually:
+
+```markdown
+---
+id: 00000000-0000-0000-0000-000000000001
+created: 2026-01-05T12:00:00Z
+updated: 2026-01-05T12:00:00Z
+---
+
+# New Desktop Note
+
+Content here...
+```
+
+**⚠️ Important:**
+- `id` must be valid UUID (e.g., with uuidgen.io)
+- Timestamps in ISO8601 format
+- Frontmatter enclosed with `---`
+
+### Bulk Operations
+
+**Edit multiple notes at once:**
+
+1. Mount WebDAV
+2. Open all `.md` files in VS Code
+3. Find & Replace across all files (Ctrl+Shift+H)
+4. Save
+5. In app: "Import Markdown Changes"
+
+### Scripting
+
+**Example: Sort all notes by date**
+
+```bash
+#!/bin/bash
+cd /mnt/notes-md/
+
+# Sort all .md files by update date
+for file in *.md; do
+  updated=$(grep "^updated:" "$file" | cut -d' ' -f2)
+  echo "$updated $file"
+done | sort
+```
+
+---
+
+## ❌ Troubleshooting
+
+### "404 Not Found" when mounting WebDAV
+
+**Cause:** `/notes-md/` folder doesn't exist
+
+**Solution:**
+1. **Perform first sync** - Folder is created automatically
+2. OR: Create manually via terminal:
+   ```bash
+   curl -X MKCOL -u noteuser:password http://server:8080/notes-md/
+   ```
+
+### Markdown files don't appear
+
+**Cause:** Desktop integration not activated
+
+**Solution:**
+1. Settings → "Desktop Integration" ON
+2. Wait for initial export
+3. Refresh WebDAV folder
+
+### Changes from desktop don't appear in app
+
+**Cause:** Markdown import not executed
+
+**Solution:**
+1. Settings → "Import Markdown Changes"
+2. OR: Wait for auto-sync (future feature)
+
+### "Frontmatter missing" error
+
+**Cause:** `.md` file without valid YAML frontmatter
+
+**Solution:**
+1. Open file in editor
+2. Add frontmatter at the beginning:
+   ```yaml
+   ---
+   id: NEW-UUID-HERE
+   created: 2026-01-05T12:00:00Z
+   updated: 2026-01-05T12:00:00Z
+   ---
+   ```
+3. Save and import again
+
+---
+
+## 🔒 Security & Best Practices
+
+### Do's ✅
+
+- ✅ **Backup before bulk edits** - Create local backup
+- ✅ **One editor at a time** - Don't edit in app AND desktop in parallel
+- ✅ **Wait for sync** - Run sync before desktop editing
+- ✅ **Respect frontmatter** - Don't change manually (unless you know what you're doing)
+
+### Don'ts ❌
+
+- ❌ **Parallel editing** - App and desktop simultaneously → conflicts
+- ❌ **Delete frontmatter** - Note can't be imported anymore
+- ❌ **Change IDs** - Note is recognized as new
+- ❌ **Manipulate timestamps** - Conflict resolution doesn't work
+
+### Recommended Workflow
+
+```
+1. Sync in app (pull-to-refresh)
+2. Open desktop
+3. Make changes
+4. Save
+5. In app: "Import Markdown Changes"
+6. Verify
+7. Run another sync
+```
+
+---
+
+## 📊 Comparison: JSON vs Markdown
+
+| Aspect | JSON | Markdown |
+|--------|------|----------|
+| **Format** | Structured | Flowing text |
+| **Readability (human)** | ⚠️ Medium | ✅ Good |
+| **Readability (machine)** | ✅ Perfect | ⚠️ Parsing needed |
+| **Metadata** | Native | Frontmatter |
+| **Editors** | Code editors | All text editors |
+| **Sync speed** | ✅ Fast | ⚠️ Slower |
+| **Reliability** | ✅ 100% | ⚠️ Frontmatter errors possible |
+| **Mobile-first** | ✅ Yes | ❌ No |
+| **Desktop-first** | ❌ No | ✅ Yes |
+
+**Conclusion:** Using both formats = Best experience on both platforms!
+
+---
+
+## 🔮 Future Features
+
+Planned for v1.3.0+:
+
+- ⏳ **Auto-Markdown-import** - Automatically on every sync
+- ⏳ **Bidirectional sync** - Without manual import
+- ⏳ **Markdown preview** - In the app
+- ⏳ **Conflict UI** - On simultaneous changes
+- ⏳ **Tags in frontmatter** - Synchronized with app
+- ⏳ **Attachments** - Images/files in Markdown
+
+---
+
+**📚 See also:**
+- [QUICKSTART.en.md](../QUICKSTART.en.md) - App setup
+- [FEATURES.en.md](FEATURES.en.md) - Complete feature list
+- [BACKUP.en.md](BACKUP.en.md) - Backup & restore
+
+**Last update:** v1.2.1 (2026-01-05)

docs/DESKTOP.md

@@ -0,0 +1,505 @@
+# Desktop-Integration 🖥️
+
+**🌍 Languages:** **Deutsch** · [English](DESKTOP.en.md)
+
+> Bearbeite deine Notizen mit jedem Markdown-Editor auf dem Desktop
+
+---
+
+## 📋 Übersicht
+
+Die Desktop-Integration ermöglicht dir, Notizen auf dem PC/Mac zu bearbeiten:
+- 📝 Jeder Markdown-Editor funktioniert
+- 🔄 Automatische Synchronisation über WebDAV
+- 💾 Dual-Format: JSON (Master) + Markdown (Mirror)
+- ⚡ Last-Write-Wins Konfliktauflösung
+
+---
+
+## 🎯 Warum Markdown?
+
+### Dual-Format Architektur
+
+```
+┌─────────────────────────────────────┐
+│         Android App                 │
+│                                     │
+│  ┌──────────┐      ┌─────────────┐ │
+│  │   JSON   │ ──→  │  Markdown   │ │
+│  │ (Master) │      │  (Mirror)   │ │
+│  └──────────┘      └─────────────┘ │
+└────────┬────────────────┬───────────┘
+         │                │
+         ↓                ↓
+    WebDAV Server
+         │                │
+    ┌────┴────┐      ┌────┴──────┐
+    │ /notes/ │      │ /notes-md/│
+    │ *.json  │      │ *.md      │
+    └─────────┘      └───────────┘
+         ↑                ↑
+         │                │
+    ┌────┴────────────────┴───────────┐
+    │      Desktop Editor              │
+    │  (VS Code, Typora, etc.)         │
+    └──────────────────────────────────┘
+```
+
+### Vorteile
+
+**JSON (Master):**
+- ✅ Zuverlässig und schnell
+- ✅ Strukturierte Daten (IDs, Timestamps)
+- ✅ Primärer Sync-Mechanismus
+- ✅ Immer aktiv
+
+**Markdown (Mirror):**
+- ✅ Menschenlesbar
+- ✅ Desktop-Editor kompatibel
+- ✅ Syntax-Highlighting
+- ✅ Optional aktivierbar
+
+---
+
+## 🚀 Schnellstart
+
+### 1. Erste Synchronisation
+
+**Wichtig:** Führe ZUERST einen Sync durch, bevor du Desktop-Integration aktivierst!
+
+1. **App einrichten** (siehe [QUICKSTART.md](QUICKSTART.md))
+2. **Server-Verbindung testen**
+3. **Erste Notiz erstellen**
+4. **Synchronisieren** (Pull-to-Refresh oder Auto-Sync)
+5. ✅ Server erstellt automatisch `/notes/` und `/notes-md/` Ordner
+
+### 2. Desktop-Integration aktivieren
+
+1. **Einstellungen** → **Desktop-Integration**
+2. **Toggle aktivieren**
+3. **Initial Export startet** - Zeigt Progress (X/Y)
+4. ✅ Alle bestehenden Notizen werden als `.md` exportiert
+
+### 3. WebDAV als Netzlaufwerk mounten
+
+#### Windows
+
+```
+1. Explorer öffnen
+2. Rechtsklick auf "Dieser PC"
+3. "Netzlaufwerk verbinden"
+4. URL eingeben: http://DEIN-SERVER:8080/notes-md/
+5. Benutzername: noteuser
+6. Passwort: (dein WebDAV-Passwort)
+7. Laufwerksbuchstabe: Z:\ (oder beliebig)
+8. Fertig!
+```
+
+**Zugriff:** `Z:\` im Explorer
+
+#### macOS
+
+```
+1. Finder öffnen
+2. Menü "Gehe zu" → "Mit Server verbinden" (⌘K)
+3. Server-Adresse: http://DEIN-SERVER:8080/notes-md/
+4. Verbinden
+5. Benutzername: noteuser
+6. Passwort: (dein WebDAV-Passwort)
+7. Fertig!
+```
+
+**Zugriff:** Finder → Netzwerk → notes-md
+
+#### Linux (GNOME)
+
+```
+1. Files / Nautilus öffnen
+2. "Andere Orte"
+3. "Mit Server verbinden"
+4. Server-Adresse: dav://DEIN-SERVER:8080/notes-md/
+5. Benutzername: noteuser
+6. Passwort: (dein WebDAV-Passwort)
+7. Fertig!
+```
+
+**Zugriff:** `/run/user/1000/gvfs/dav:host=...`
+
+#### Linux (davfs2 - permanent)
+
+```bash
+# Installation
+sudo apt install davfs2
+
+# Mount-Point erstellen
+sudo mkdir -p /mnt/notes-md
+
+# Einmalig mounten
+sudo mount -t davfs http://DEIN-SERVER:8080/notes-md/ /mnt/notes-md
+
+# Permanent in /etc/fstab
+echo "http://DEIN-SERVER:8080/notes-md/ /mnt/notes-md davfs rw,user,noauto 0 0" | sudo tee -a /etc/fstab
+```
+
+**Zugriff:** `/mnt/notes-md/`
+
+---
+
+## 📝 Markdown-Editoren
+
+### Empfohlene Editoren
+
+#### 1. VS Code ⭐ _Empfohlen_
+
+**Vorteile:**
+- ✅ Kostenlos & Open Source
+- ✅ Markdown-Preview (Ctrl+Shift+V)
+- ✅ Syntax-Highlighting
+- ✅ Git-Integration
+- ✅ Erweiterungen (Spell Check, etc.)
+
+**Setup:**
+```
+1. VS Code installieren
+2. WebDAV-Laufwerk mounten
+3. Ordner öffnen: Z:\notes-md\ (Windows) oder /mnt/notes-md (Linux)
+4. Fertig! Markdown-Dateien bearbeiten
+```
+
+**Extensions (optional):**
+- `Markdown All in One` - Shortcuts & Preview
+- `Markdown Preview Enhanced` - Bessere Preview
+- `Code Spell Checker` - Rechtschreibprüfung
+
+#### 2. Typora
+
+**Vorteile:**
+- ✅ WYSIWYG Markdown-Editor
+- ✅ Minimalistisches Design
+- ✅ Live-Preview
+- ⚠️ Kostenpflichtig (~15€)
+
+**Setup:**
+```
+1. Typora installieren
+2. WebDAV mounten
+3. Ordner in Typora öffnen
+4. Notizen bearbeiten
+```
+
+#### 3. Notepad++
+
+**Vorteile:**
+- ✅ Leichtgewichtig
+- ✅ Schnell
+- ✅ Syntax-Highlighting
+- ⚠️ Keine Markdown-Preview
+
+**Setup:**
+```
+1. Notepad++ installieren
+2. WebDAV mounten
+3. Dateien direkt öffnen
+```
+
+#### 4. Obsidian
+
+**Vorteile:**
+- ✅ Zweite Gehirn-Philosophie
+- ✅ Graph-View für Verlinkungen
+- ✅ Viele Plugins
+- ⚠️ Sync-Konflikte möglich (2 Master)
+
+**Setup:**
+```
+1. Obsidian installieren
+2. WebDAV als Vault öffnen
+3. Vorsicht: Obsidian erstellt eigene Metadaten!
+```
+
+**⚠️ Nicht empfohlen:** Kann Frontmatter verändern
+
+---
+
+## 📄 Markdown-Dateiformat
+
+### Struktur
+
+Jede Notiz wird als `.md` Datei mit YAML-Frontmatter exportiert:
+
+```markdown
+---
+id: abc-123-def-456
+created: 2026-01-05T14:30:22Z
+updated: 2026-01-05T14:30:22Z
+tags: []
+---
+
+# Notiz-Titel
+
+Notiz-Inhalt hier...
+```
+
+### Frontmatter-Felder
+
+| Feld | Typ | Beschreibung | Pflicht |
+|------|-----|--------------|---------|
+| `id` | UUID | Eindeutige Notiz-ID | ✅ Ja |
+| `created` | ISO8601 | Erstellungsdatum | ✅ Ja |
+| `updated` | ISO8601 | Änderungsdatum | ✅ Ja |
+| `tags` | Array | Tags (zukünftig) | ❌ Nein |
+
+### Dateinamen
+
+**Sanitization-Regeln:**
+```
+Titel: "Meine Einkaufsliste 🛒"
+→ Dateiname: "Meine_Einkaufsliste.md"
+
+Entfernt werden:
+- Emojis: 🛒 → entfernt
+- Sonderzeichen: / \ : * ? " < > | → entfernt
+- Mehrfache Leerzeichen → einzelnes Leerzeichen
+- Leerzeichen → Unterstrich _
+```
+
+**Beispiele:**
+```
+"Meeting Notes 2026" → "Meeting_Notes_2026.md"
+"To-Do: Projekt" → "To-Do_Projekt.md"
+"Urlaub ☀️" → "Urlaub.md"
+```
+
+---
+
+## 🔄 Synchronisation
+
+### Workflow: Android → Desktop
+
+1. **Notiz in App erstellen/bearbeiten**
+2. **Sync ausführen** (Auto oder manuell)
+3. **JSON wird hochgeladen** (`/notes/abc-123.json`)
+4. **Markdown wird exportiert** (`/notes-md/Notiz_Titel.md`) _(nur wenn Desktop-Integration AN)_
+5. **Desktop-Editor zeigt Änderungen** (nach Refresh)
+
+### Workflow: Desktop → Android
+
+1. **Markdown-Datei bearbeiten** (im gemounteten Ordner)
+2. **Speichern** - Datei liegt sofort auf Server
+3. **In App: Markdown-Import ausführen**
+   - Einstellungen → "Import Markdown Changes"
+   - Oder: Auto-Import bei jedem Sync (zukünftig)
+4. **App übernimmt Änderungen** (wenn Desktop-Version neuer)
+
+### Konfliktauflösung: Last-Write-Wins
+
+**Regel:** Neueste Version (nach `updated` Timestamp) gewinnt
+
+**Beispiel:**
+```
+App-Version:     updated: 2026-01-05 14:00
+Desktop-Version: updated: 2026-01-05 14:30
+→ Desktop gewinnt (neuerer Timestamp)
+```
+
+**Automatisch:**
+- ✅ Beim Markdown-Import
+- ✅ Beim JSON-Sync
+- ⚠️ Keine Merge-Konflikte - nur komplettes Überschreiben
+
+---
+
+## ⚙️ Einstellungen
+
+### Desktop-Integration Toggle
+
+**Einstellungen → Desktop-Integration**
+
+**AN (aktiviert):**
+- ✅ Neue Notizen → automatisch als `.md` exportiert
+- ✅ Aktualisierte Notizen → `.md` Update
+- ✅ Gelöschte Notizen → `.md` bleibt (zukünftig: auch löschen)
+
+**AUS (deaktiviert):**
+- ❌ Kein Markdown-Export
+- ✅ JSON-Sync läuft normal weiter
+- ✅ Bestehende `.md` Dateien bleiben erhalten
+
+### Initial Export
+
+**Was passiert beim Aktivieren:**
+1. Alle bestehenden Notizen werden gescannt
+2. Progress-Dialog zeigt Fortschritt (z.B. "23/42")
+3. Jede Notiz wird als `.md` exportiert
+4. Bei Fehlern: Einzelne Notiz wird übersprungen
+5. Erfolgsmeldung mit Anzahl exportierter Notizen
+
+**Zeit:** ~1-2 Sekunden pro 50 Notizen
+
+---
+
+## 🛠️ Erweiterte Nutzung
+
+### Manuelle Markdown-Erstellung
+
+Du kannst `.md` Dateien manuell erstellen:
+
+```markdown
+---
+id: 00000000-0000-0000-0000-000000000001
+created: 2026-01-05T12:00:00Z
+updated: 2026-01-05T12:00:00Z
+---
+
+# Neue Desktop-Notiz
+
+Inhalt hier...
+```
+
+**⚠️ Wichtig:**
+- `id` muss gültige UUID sein (z.B. mit uuidgen.io)
+- Timestamps in ISO8601-Format
+- Frontmatter mit `---` umschließen
+
+### Bulk-Operations
+
+**Mehrere Notizen auf einmal bearbeiten:**
+
+1. WebDAV mounten
+2. Alle `.md` Dateien in VS Code öffnen
+3. Suchen & Ersetzen über alle Dateien (Ctrl+Shift+H)
+4. Speichern
+5. In App: "Import Markdown Changes"
+
+### Scripting
+
+**Beispiel: Alle Notizen nach Datum sortieren**
+
+```bash
+#!/bin/bash
+cd /mnt/notes-md/
+
+# Alle .md Dateien nach Update-Datum sortieren
+for file in *.md; do
+  updated=$(grep "^updated:" "$file" | cut -d' ' -f2)
+  echo "$updated $file"
+done | sort
+```
+
+---
+
+## ❌ Fehlerbehebung
+
+### "404 Not Found" beim WebDAV-Mount
+
+**Ursache:** `/notes-md/` Ordner existiert nicht
+
+**Lösung:**
+1. **Erste Sync durchführen** - Ordner wird automatisch erstellt
+2. ODER: Manuell erstellen via Terminal:
+   ```bash
+   curl -X MKCOL -u noteuser:password http://server:8080/notes-md/
+   ```
+
+### Markdown-Dateien erscheinen nicht
+
+**Ursache:** Desktop-Integration nicht aktiviert
+
+**Lösung:**
+1. Einstellungen → "Desktop-Integration" AN
+2. Warten auf Initial Export
+3. WebDAV-Ordner refreshen
+
+### Änderungen vom Desktop erscheinen nicht in App
+
+**Ursache:** Markdown-Import nicht ausgeführt
+
+**Lösung:**
+1. Einstellungen → "Import Markdown Changes"
+2. ODER: Auto-Sync abwarten (zukünftiges Feature)
+
+### "Frontmatter fehlt" Fehler
+
+**Ursache:** `.md` Datei ohne gültiges YAML-Frontmatter
+
+**Lösung:**
+1. Datei in Editor öffnen
+2. Frontmatter am Anfang hinzufügen:
+   ```yaml
+   ---
+   id: NEUE-UUID-HIER
+   created: 2026-01-05T12:00:00Z
+   updated: 2026-01-05T12:00:00Z
+   ---
+   ```
+3. Speichern und erneut importieren
+
+---
+
+## 🔒 Sicherheit & Best Practices
+
+### Do's ✅
+
+- ✅ **Backup vor Bulk-Edits** - Lokales Backup erstellen
+- ✅ **Ein Editor zur Zeit** - Nicht parallel in App UND Desktop bearbeiten
+- ✅ **Sync abwarten** - Vor Desktop-Bearbeitung Sync durchführen
+- ✅ **Frontmatter respektieren** - Nicht manuell ändern (außer du weißt was du tust)
+
+### Don'ts ❌
+
+- ❌ **Parallel bearbeiten** - App und Desktop gleichzeitig → Konflikte
+- ❌ **Frontmatter löschen** - Notiz kann nicht mehr importiert werden
+- ❌ **IDs ändern** - Notiz wird als neue erkannt
+- ❌ **Timestamps manipulieren** - Konfliktauflösung funktioniert nicht
+
+### Empfohlener Workflow
+
+```
+1. Sync in App (Pull-to-Refresh)
+2. Desktop öffnen
+3. Änderungen machen
+4. Speichern
+5. In App: "Import Markdown Changes"
+6. Überprüfen
+7. Weiteren Sync durchführen
+```
+
+---
+
+## 📊 Vergleich: JSON vs Markdown
+
+| Aspekt | JSON | Markdown |
+|--------|------|----------|
+| **Format** | Strukturiert | Fließtext |
+| **Lesbarkeit (Mensch)** | ⚠️ Mittel | ✅ Gut |
+| **Lesbarkeit (Maschine)** | ✅ Perfekt | ⚠️ Parsing nötig |
+| **Metadata** | Native | Frontmatter |
+| **Editoren** | Code-Editoren | Alle Text-Editoren |
+| **Sync-Geschwindigkeit** | ✅ Schnell | ⚠️ Langsamer |
+| **Zuverlässigkeit** | ✅ 100% | ⚠️ Frontmatter-Fehler möglich |
+| **Mobile-First** | ✅ Ja | ❌ Nein |
+| **Desktop-First** | ❌ Nein | ✅ Ja |
+
+**Fazit:** Beide Formate nutzen = Beste Erfahrung auf beiden Plattformen!
+
+---
+
+## 🔮 Zukünftige Features
+
+Geplant für v1.3.0+:
+
+- ⏳ **Auto-Markdown-Import** - Bei jedem Sync automatisch
+- ⏳ **Bidirektionaler Sync** - Ohne manuellen Import
+- ⏳ **Markdown-Vorschau** - In der App
+- ⏳ **Konflikts-UI** - Bei gleichzeitigen Änderungen
+- ⏳ **Tags in Frontmatter** - Synchronisiert mit App
+- ⏳ **Attachments** - Bilder/Dateien in Markdown
+
+---
+
+**📚 Siehe auch:**
+- [QUICKSTART.md](../QUICKSTART.md) - App-Einrichtung
+- [FEATURES.md](FEATURES.md) - Vollständige Feature-Liste
+- [BACKUP.md](BACKUP.md) - Backup & Wiederherstellung
+
+**Letzte Aktualisierung:** v1.2.1 (2026-01-05)

docs/FEATURES.en.md

@@ -0,0 +1,275 @@
+# Complete Feature List 📋
+
+**🌍 Languages:** [Deutsch](FEATURES.md) · **English**
+
+> All features of Simple Notes Sync in detail
+
+---
+
+## 📝 Note Management
+
+### Basic Features
+- ✅ **Simple text notes** - Focus on content, no distractions
+- ✅ **Auto-save** - No manual saving needed
+- ✅ **Title + content** - Clear structure for each note
+- ✅ **Timestamps** - Creation and modification date automatically
+- ✅ **Swipe-to-delete** - Intuitive gesture for deletion
+- ✅ **Confirmation dialog** - Protection against accidental deletion
+- ✅ **Material Design 3** - Modern, clean UI
+- ✅ **Dark mode** - Automatically based on system settings
+- ✅ **Dynamic colors** - Adapts to your Android theme
+
+### Editor
+- ✅ **Minimalist editor** - No bells and whistles
+- ✅ **Auto-focus** - Start writing immediately
+- ✅ **Fullscreen mode** - Maximum writing space
+- ✅ **Save button** - Manual confirmation possible
+- ✅ **Back navigation** - Saves automatically
+
+---
+
+## 💾 Backup & Restore
+
+### Local Backup System
+- ✅ **JSON export** - All notes in one file
+- ✅ **Free location choice** - Downloads, SD card, cloud folder
+- ✅ **Filenames with timestamp** - `simplenotes_backup_YYYY-MM-DD_HHmmss.json`
+- ✅ **Complete export** - Title, content, timestamps, IDs
+- ✅ **Human-readable format** - JSON with formatting
+- ✅ **Independent from server** - Works completely offline
+
+### Restore Modes
+- ✅ **Merge** - Add new notes, keep existing ones _(Default)_
+- ✅ **Replace** - Delete all and import backup
+- ✅ **Overwrite duplicates** - Backup wins on ID conflicts
+- ✅ **Automatic safety backup** - Before every restore
+- ✅ **Backup validation** - Checks format and version
+- ✅ **Error handling** - Clear error messages on issues
+
+---
+
+## 🖥️ Desktop Integration
+
+### Markdown Export
+- ✅ **Automatic export** - Each note → `.md` file
+- ✅ **Dual-format** - JSON (master) + Markdown (mirror)
+- ✅ **Filename sanitization** - Safe filenames from titles
+- ✅ **Frontmatter metadata** - YAML with ID, timestamps, tags
+- ✅ **WebDAV sync** - Parallel to JSON sync
+- ✅ **Optional** - Toggle in settings
+- ✅ **Initial export** - All existing notes when activated
+- ✅ **Progress indicator** - Shows X/Y during export
+
+### Markdown Import
+- ✅ **Desktop → App** - Import changes from desktop
+- ✅ **Last-Write-Wins** - Conflict resolution via timestamp
+- ✅ **Frontmatter parsing** - Reads metadata from `.md` files
+- ✅ **Detect new notes** - Automatically adopt to app
+- ✅ **Detect updates** - Only if desktop version is newer
+- ✅ **Error tolerance** - Individual errors don't abort import
+
+### WebDAV Access
+- ✅ **Network drive mount** - Windows, macOS, Linux
+- ✅ **Any Markdown editor** - VS Code, Typora, Notepad++, iA Writer
+- ✅ **Live editing** - Direct access to `.md` files
+- ✅ **Folder structure** - `/notes/` for JSON, `/notes-md/` for Markdown
+- ✅ **Automatic folder creation** - On first sync
+
+---
+
+## 🔄 Synchronization
+
+### Auto-Sync
+- ✅ **Interval selection** - 15, 30 or 60 minutes
+- ✅ **WiFi binding** - Only in configured home WiFi
+- ✅ **Battery-friendly** - ~0.2-0.8% per day
+- ✅ **Smart server check** - No errors on foreign networks
+- ✅ **WorkManager** - Reliable background execution
+- ✅ **Battery optimization compatible** - Works even with Doze mode
+
+### Sync Triggers (6 total)
+1. ✅ **Periodic sync** - Automatically after interval
+2. ✅ **App-start sync** - When opening the app
+3. ✅ **WiFi-connect sync** - When home WiFi connects
+4. ✅ **Manual sync** - Button in settings
+5. ✅ **Pull-to-refresh** - Swipe gesture in notes list
+6. ✅ **Settings-save sync** - After server configuration
+
+### Sync Mechanism
+- ✅ **Upload** - Local changes to server
+- ✅ **Download** - Server changes to app
+- ✅ **Conflict detection** - On simultaneous changes
+- ✅ **Conflict-free merging** - Last-Write-Wins via timestamp
+- ✅ **Sync status tracking** - LOCAL_ONLY, PENDING, SYNCED, CONFLICT
+- ✅ **Error handling** - Retry on network issues
+- ✅ **Offline-first** - App works without server
+
+### Server Connection
+- ✅ **WebDAV protocol** - Standard protocol
+- ✅ **HTTP/HTTPS** - HTTP only local, HTTPS for external
+- ✅ **Username/password** - Basic authentication
+- ✅ **Connection test** - Test in settings
+- ✅ **Gateway SSID** - WiFi name for auto-sync
+- ✅ **Server URL normalization** - Automatic `/notes/` and `/notes-md/` _(NEW in v1.2.1)_
+- ✅ **Flexible URL input** - Both variants work: `http://server/` and `http://server/notes/`
+
+---
+
+## 🔒 Privacy & Security
+
+### Self-Hosted
+- ✅ **Own server** - Full control over data
+- ✅ **No cloud** - No third parties
+- ✅ **No tracking** - No analytics, no telemetry
+- ✅ **No account** - Only server credentials
+- ✅ **100% open source** - MIT License
+
+### Data Security
+- ✅ **Local storage** - App-private storage (Android)
+- ✅ **WebDAV encryption** - HTTPS for external servers
+- ✅ **Password storage** - Android SharedPreferences (encrypted)
+- ✅ **No third-party libs** - Only Android SDK + Sardine (WebDAV)
+
+### Developer Features
+- ✅ **File logging** - Optional, only when enabled _(NEW in v1.3.2)_
+- ✅ **Privacy notice** - Explicit warning on activation
+- ✅ **Local logs** - Logs stay on device
+
+---
+
+## 🔋 Performance & Optimization
+
+### Battery Efficiency
+- ✅ **Optimized sync intervals** - 15/30/60 min
+- ✅ **WiFi-only** - No mobile data sync
+- ✅ **Smart server check** - Only in home WiFi
+- ✅ **WorkManager** - System-optimized execution
+- ✅ **Doze mode compatible** - Sync runs even in standby
+- ✅ **Measured consumption:**
+  - 15 min: ~0.8% / day (~23 mAh)
+  - 30 min: ~0.4% / day (~12 mAh) ⭐ _Recommended_
+  - 60 min: ~0.2% / day (~6 mAh)
+
+### App Performance
+- ✅ **Offline-first** - Works without internet
+- ✅ **Instant-load** - Notes load in <100ms
+- ✅ **Smooth scrolling** - RecyclerView with ViewHolder
+- ✅ **Material Design 3** - Native Android UI
+- ✅ **Kotlin Coroutines** - Asynchronous operations
+- ✅ **Minimal APK size** - ~2 MB
+
+---
+
+## 🛠️ Technical Details
+
+### Platform
+- ✅ **Android 8.0+** (API 26+)
+- ✅ **Target SDK 36** (Android 15)
+- ✅ **Kotlin** - Modern programming language
+- ✅ **Material Design 3** - Latest design guidelines
+- ✅ **ViewBinding** - Type-safe view references
+
+### Architecture
+- ✅ **MVVM-Light** - Simple architecture
+- ✅ **Single Activity** - Modern navigation
+- ✅ **Kotlin Coroutines** - Async/Await pattern
+- ✅ **Dispatchers.IO** - Background operations
+- ✅ **SharedPreferences** - Settings storage
+- ✅ **File-based storage** - JSON files locally
+- ✅ **Custom exceptions** - Dedicated SyncException for better error handling _(NEW in v1.3.2)_
+
+### Dependencies
+- ✅ **AndroidX** - Jetpack libraries
+- ✅ **Material Components** - Material Design 3
+- ✅ **Sardine** - WebDAV client (com.thegrizzlylabs)
+- ✅ **Gson** - JSON serialization
+- ✅ **WorkManager** - Background tasks
+- ✅ **OkHttp** - HTTP client (via Sardine)
+
+### Build Variants
+- ✅ **Standard** - Universal APK (100% FOSS, no Google dependencies)
+- ✅ **F-Droid** - Identical to Standard (100% FOSS)
+- ✅ **Debug/Release** - Development and production
+- ✅ **No Google Services** - Completely FOSS, no proprietary libraries
+
+---
+
+## 📦 Server Compatibility
+
+### Tested WebDAV Servers
+- ✅ **Docker WebDAV** (recommended for self-hosting)
+- ✅ **Nextcloud** - Fully compatible
+- ✅ **ownCloud** - Works perfectly
+- ✅ **Apache mod_dav** - Standard WebDAV
+- ✅ **nginx + WebDAV** - With correct configuration
+
+### Server Features
+- ✅ **Basic Auth** - Username/password
+- ✅ **Directory listing** - For download
+- ✅ **PUT/GET** - Upload/download
+- ✅ **MKCOL** - Create folders
+- ✅ **DELETE** - Delete notes (future)
+
+---
+
+## 🔮 Future Features
+
+Planned for upcoming versions:
+
+### v1.4.0 - Checklists
+- ⏳ **Checklist notes** - New note type with checkboxes
+- ⏳ **Completed items** - Strike-through/check off
+- ⏳ **Drag & drop** - Reorder items
+
+### v1.5.0 - Internationalization
+- ⏳ **Multi-language** - German + English UI
+- ⏳ **Language selection** - Selectable in settings
+- ⏳ **Full translation** - All strings in both languages
+
+### v1.6.0 - Modern APIs
+- ⏳ **Replace LocalBroadcastManager** - Use SharedFlow instead
+- ⏳ **PackageInfo Flags** - Use PackageInfoFlags.of()
+- ⏳ **Complexity refactoring** - Split long functions
+
+---
+
+## 📊 Comparison with Other Apps
+
+| Feature | Simple Notes Sync | Google Keep | Nextcloud Notes |
+|---------|------------------|-------------|-----------------|
+| Offline-first | ✅ | ⚠️ Limited | ⚠️ Limited |
+| Self-hosted | ✅ | ❌ | ✅ |
+| Auto-sync | ✅ | ✅ | ✅ |
+| Markdown export | ✅ | ❌ | ✅ |
+| Desktop access | ✅ (WebDAV) | ✅ (Web) | ✅ (Web + WebDAV) |
+| Local backup | ✅ | ❌ | ⚠️ Server backup |
+| No Google account | ✅ | ❌ | ✅ |
+| Open source | ✅ MIT | ❌ | ✅ AGPL |
+| APK size | ~2 MB | ~50 MB | ~8 MB |
+| Battery usage | ~0.4%/day | ~1-2%/day | ~0.5%/day |
+
+---
+
+## ❓ FAQ
+
+**Q: Do I need a server?**  
+A: No! The app works completely offline. The server is optional for sync.
+
+**Q: Which server is best?**  
+A: For beginners: Docker WebDAV (simple, easy). For pros: Nextcloud (many features).
+
+**Q: Does Markdown export work without Desktop Integration?**  
+A: No, you need to activate the feature in settings.
+
+**Q: Will my data be lost if I switch servers?**  
+A: No! Create a local backup, switch servers, restore.
+
+**Q: Why JSON + Markdown?**  
+A: JSON is reliable and fast (master). Markdown is human-readable (mirror for desktop).
+
+**Q: Can I use the app without Google Play?**  
+A: Yes! Download the APK directly from GitHub or use F-Droid.
+
+---
+
+**Last update:** v1.3.2 (2026-01-10)

docs/FEATURES.md

@@ -0,0 +1,275 @@
+# Vollständige Feature-Liste 📋
+
+**🌍 Languages:** **Deutsch** · [English](FEATURES.en.md)
+
+> Alle Features von Simple Notes Sync im Detail
+
+---
+
+## 📝 Notiz-Verwaltung
+
+### Basis-Funktionen
+- ✅ **Einfache Textnotizen** - Fokus auf Inhalt, keine Ablenkung
+- ✅ **Automatisches Speichern** - Kein manuelles Speichern nötig
+- ✅ **Titel + Inhalt** - Klare Struktur für jede Notiz
+- ✅ **Zeitstempel** - Erstellungs- und Änderungsdatum automatisch
+- ✅ **Swipe-to-Delete** - Intuitive Geste zum Löschen
+- ✅ **Bestätigungs-Dialog** - Schutz vor versehentlichem Löschen
+- ✅ **Material Design 3** - Moderne, saubere UI
+- ✅ **Dark Mode** - Automatisch je nach System-Einstellung
+- ✅ **Dynamic Colors** - Passt sich deinem Android-Theme an
+
+### Editor
+- ✅ **Minimalistischer Editor** - Kein Schnickschnack
+- ✅ **Auto-Fokus** - Direkt losschreiben
+- ✅ **Vollbild-Modus** - Maximale Schreibfläche
+- ✅ **Speichern-Button** - Manuelle Bestätigung möglich
+- ✅ **Zurück-Navigation** - Speichert automatisch
+
+---
+
+## 💾 Backup & Wiederherstellung
+
+### Lokales Backup System
+- ✅ **JSON-Export** - Alle Notizen in einer Datei
+- ✅ **Freie Speicherort-Wahl** - Downloads, SD-Karte, Cloud-Ordner
+- ✅ **Dateinamen mit Zeitstempel** - `simplenotes_backup_YYYY-MM-DD_HHmmss.json`
+- ✅ **Vollständiger Export** - Titel, Inhalt, Timestamps, IDs
+- ✅ **Menschenlesbares Format** - JSON mit Formatierung
+- ✅ **Unabhängig vom Server** - Funktioniert komplett offline
+
+### Wiederherstellungs-Modi
+- ✅ **Zusammenführen (Merge)** - Neue Notizen hinzufügen, bestehende behalten _(Standard)_
+- ✅ **Ersetzen (Replace)** - Alle löschen und Backup importieren
+- ✅ **Duplikate überschreiben (Overwrite)** - Backup gewinnt bei ID-Konflikten
+- ✅ **Automatisches Sicherheits-Backup** - Vor jeder Wiederherstellung
+- ✅ **Backup-Validierung** - Prüft Format und Version
+- ✅ **Fehlerbehandlung** - Klare Fehlermeldungen bei Problemen
+
+---
+
+## 🖥️ Desktop-Integration
+
+### Markdown-Export
+- ✅ **Automatischer Export** - Jede Notiz → `.md` Datei
+- ✅ **Dual-Format** - JSON (Master) + Markdown (Mirror)
+- ✅ **Dateinamen-Sanitization** - Sichere Dateinamen aus Titeln
+- ✅ **Frontmatter-Metadata** - YAML mit ID, Timestamps, Tags
+- ✅ **WebDAV-Sync** - Parallel zum JSON-Sync
+- ✅ **Optional** - In Einstellungen ein/ausschaltbar
+- ✅ **Initial Export** - Alle bestehenden Notizen beim Aktivieren
+- ✅ **Progress-Anzeige** - Zeigt X/Y beim Export
+
+### Markdown-Import
+- ✅ **Desktop → App** - Änderungen vom Desktop importieren
+- ✅ **Last-Write-Wins** - Konfliktauflösung via Timestamp
+- ✅ **Frontmatter-Parsing** - Liest Metadata aus `.md` Dateien
+- ✅ **Neue Notizen erkennen** - Automatisch in App übernehmen
+- ✅ **Updates erkennen** - Nur wenn Desktop-Version neuer ist
+- ✅ **Fehlertoleranz** - Einzelne Fehler brechen Import nicht ab
+
+### WebDAV-Zugriff
+- ✅ **Network Drive Mount** - Windows, macOS, Linux
+- ✅ **Jeder Markdown-Editor** - VS Code, Typora, Notepad++, iA Writer
+- ✅ **Live-Bearbeitung** - Direkter Zugriff auf `.md` Dateien
+- ✅ **Ordner-Struktur** - `/notes/` für JSON, `/notes-md/` für Markdown
+- ✅ **Automatische Ordner-Erstellung** - Beim ersten Sync
+
+---
+
+## 🔄 Synchronisation
+
+### Auto-Sync
+- ✅ **Intervall-Auswahl** - 15, 30 oder 60 Minuten
+- ✅ **WLAN-Bindung** - Nur im konfigurierten Heim-WLAN
+- ✅ **Akkuschonend** - ~0.2-0.8% pro Tag
+- ✅ **Smart Server-Check** - Keine Fehler in fremden Netzwerken
+- ✅ **WorkManager** - Zuverlässige Background-Ausführung
+- ✅ **Battery-Optimierung kompatibel** - Funktioniert auch mit Doze Mode
+
+### Sync-Trigger (6 Stück)
+1. ✅ **Periodic Sync** - Automatisch nach Intervall
+2. ✅ **App-Start Sync** - Beim Öffnen der App
+3. ✅ **WiFi-Connect Sync** - Wenn Heim-WLAN verbindet
+4. ✅ **Manual Sync** - Button in Einstellungen
+5. ✅ **Pull-to-Refresh** - Wisch-Geste in Notizliste
+6. ✅ **Settings-Save Sync** - Nach Server-Konfiguration
+
+### Sync-Mechanismus
+- ✅ **Upload** - Lokale Änderungen zum Server
+- ✅ **Download** - Server-Änderungen in App
+- ✅ **Konflikt-Erkennung** - Bei gleichzeitigen Änderungen
+- ✅ **Konfliktfreies Merging** - Last-Write-Wins via Timestamp
+- ✅ **Sync-Status Tracking** - LOCAL_ONLY, PENDING, SYNCED, CONFLICT
+- ✅ **Fehlerbehandlung** - Retry bei Netzwerkproblemen
+- ✅ **Offline-First** - App funktioniert ohne Server
+
+### Server-Verbindung
+- ✅ **WebDAV-Protokoll** - Standard-Protokoll
+- ✅ **HTTP/HTTPS** - HTTP nur lokal, HTTPS für extern
+- ✅ **Username/Password** - Basic Authentication
+- ✅ **Connection Test** - In Einstellungen testen
+- ✅ **Gateway SSID** - WLAN-Name für Auto-Sync
+- ✅ **Server-URL Normalisierung** - Automatisches `/notes/` und `/notes-md/` _(NEU in v1.2.1)_
+- ✅ **Flexible URL-Eingabe** - Beide Varianten funktionieren: `http://server/` und `http://server/notes/`
+
+---
+
+## 🔒 Privacy & Sicherheit
+
+### Self-Hosted
+- ✅ **Eigener Server** - Volle Kontrolle über Daten
+- ✅ **Keine Cloud** - Keine Drittanbieter
+- ✅ **Kein Tracking** - Keine Analytik, keine Telemetrie
+- ✅ **Kein Account** - Nur Server-Zugangsdaten
+- ✅ **100% Open Source** - MIT Lizenz
+
+### Daten-Sicherheit
+- ✅ **Lokale Speicherung** - App-Private Storage (Android)
+- ✅ **WebDAV-Verschlüsselung** - HTTPS für externe Server
+- ✅ **Passwort-Speicherung** - Android SharedPreferences (verschlüsselt)
+- ✅ **Keine Drittanbieter-Libs** - Nur Android SDK + Sardine (WebDAV)
+
+### Entwickler-Features
+- ✅ **Datei-Logging** - Optional, nur bei Aktivierung _(NEU in v1.3.2)_
+- ✅ **Datenschutz-Hinweis** - Explizite Warnung bei Aktivierung
+- ✅ **Lokale Logs** - Logs bleiben auf dem Gerät
+
+---
+
+## 🔋 Performance & Optimierung
+
+### Akku-Effizienz
+- ✅ **Optimierte Sync-Intervalle** - 15/30/60 Min
+- ✅ **WLAN-Only** - Kein Mobile Data Sync
+- ✅ **Smart Server-Check** - Nur im Heim-WLAN
+- ✅ **WorkManager** - System-optimierte Ausführung
+- ✅ **Doze Mode kompatibel** - Sync läuft auch im Standby
+- ✅ **Gemessener Verbrauch:**
+  - 15 Min: ~0.8% / Tag (~23 mAh)
+  - 30 Min: ~0.4% / Tag (~12 mAh) ⭐ _Empfohlen_
+  - 60 Min: ~0.2% / Tag (~6 mAh)
+
+### App-Performance
+- ✅ **Offline-First** - Funktioniert ohne Internet
+- ✅ **Instant-Load** - Notizen laden in <100ms
+- ✅ **Smooth Scrolling** - RecyclerView mit ViewHolder
+- ✅ **Material Design 3** - Native Android UI
+- ✅ **Kotlin Coroutines** - Asynchrone Operationen
+- ✅ **Minimale APK-Größe** - ~2 MB
+
+---
+
+## 🛠️ Technische Details
+
+### Plattform
+- ✅ **Android 8.0+** (API 26+)
+- ✅ **Target SDK 36** (Android 15)
+- ✅ **Kotlin** - Moderne Programmiersprache
+- ✅ **Material Design 3** - Neueste Design-Richtlinien
+- ✅ **ViewBinding** - Typ-sichere View-Referenzen
+
+### Architektur
+- ✅ **MVVM-Light** - Einfache Architektur
+- ✅ **Single Activity** - Moderne Navigation
+- ✅ **Kotlin Coroutines** - Async/Await Pattern
+- ✅ **Dispatchers.IO** - Background-Operationen
+- ✅ **SharedPreferences** - Settings-Speicherung
+- ✅ **File-Based Storage** - JSON-Dateien lokal
+- ✅ **Custom Exceptions** - Dedizierte SyncException für bessere Fehlerbehandlung _(NEU in v1.3.2)_
+
+### Abhängigkeiten
+- ✅ **AndroidX** - Jetpack Libraries
+- ✅ **Material Components** - Material Design 3
+- ✅ **Sardine** - WebDAV Client (com.thegrizzlylabs)
+- ✅ **Gson** - JSON Serialization
+- ✅ **WorkManager** - Background Tasks
+- ✅ **OkHttp** - HTTP Client (via Sardine)
+
+### Build-Varianten
+- ✅ **Standard** - Universal APK (100% FOSS, keine Google-Dependencies)
+- ✅ **F-Droid** - Identisch mit Standard (100% FOSS)
+- ✅ **Debug/Release** - Entwicklung und Production
+- ✅ **Keine Google Services** - Komplett FOSS, keine proprietären Bibliotheken
+
+---
+
+## 📦 Server-Kompatibilität
+
+### Getestete WebDAV-Server
+- ✅ **Docker WebDAV** (empfohlen für Self-Hosting)
+- ✅ **Nextcloud** - Vollständig kompatibel
+- ✅ **ownCloud** - Funktioniert einwandfrei
+- ✅ **Apache mod_dav** - Standard WebDAV
+- ✅ **nginx + WebDAV** - Mit korrekter Konfiguration
+
+### Server-Features
+- ✅ **Basic Auth** - Username/Password
+- ✅ **Directory Listing** - Für Download
+- ✅ **PUT/GET** - Upload/Download
+- ✅ **MKCOL** - Ordner erstellen
+- ✅ **DELETE** - Notizen löschen (zukünftig)
+
+---
+
+## 🔮 Zukünftige Features
+
+Geplant für kommende Versionen:
+
+### v1.4.0 - Checklisten
+- ⏳ **Checklisten-Notizen** - Neuer Notiz-Typ mit Checkboxen
+- ⏳ **Erledigte Items** - Durchstreichen/Abhaken
+- ⏳ **Drag & Drop** - Items neu anordnen
+
+### v1.5.0 - Internationalisierung
+- ⏳ **Mehrsprachigkeit** - Deutsch + Englisch UI
+- ⏳ **Sprachauswahl** - In Einstellungen wählbar
+- ⏳ **Vollständige Übersetzung** - Alle Strings in beiden Sprachen
+
+### v1.6.0 - Modern APIs
+- ⏳ **LocalBroadcastManager ersetzen** - SharedFlow stattdessen
+- ⏳ **PackageInfo Flags** - PackageInfoFlags.of() verwenden
+- ⏳ **Komplexitäts-Refactoring** - Lange Funktionen aufteilen
+
+---
+
+## 📊 Vergleich mit anderen Apps
+
+| Feature | Simple Notes Sync | Google Keep | Nextcloud Notes |
+|---------|------------------|-------------|-----------------|
+| Offline-First | ✅ | ⚠️ Eingeschränkt | ⚠️ Eingeschränkt |
+| Self-Hosted | ✅ | ❌ | ✅ |
+| Auto-Sync | ✅ | ✅ | ✅ |
+| Markdown-Export | ✅ | ❌ | ✅ |
+| Desktop-Zugriff | ✅ (WebDAV) | ✅ (Web) | ✅ (Web + WebDAV) |
+| Lokales Backup | ✅ | ❌ | ⚠️ Server-Backup |
+| Kein Google-Account | ✅ | ❌ | ✅ |
+| Open Source | ✅ MIT | ❌ | ✅ AGPL |
+| APK-Größe | ~2 MB | ~50 MB | ~8 MB |
+| Akku-Verbrauch | ~0.4%/Tag | ~1-2%/Tag | ~0.5%/Tag |
+
+---
+
+## ❓ FAQ
+
+**Q: Brauche ich einen Server?**  
+A: Nein! Die App funktioniert auch komplett offline. Der Server ist optional für Sync.
+
+**Q: Welcher Server ist am besten?**  
+A: Für Einstieg: Docker WebDAV (einfach, leicht). Für Profis: Nextcloud (viele Features).
+
+**Q: Funktioniert Markdown-Export ohne Desktop-Integration?**  
+A: Nein, du musst das Feature in den Einstellungen aktivieren.
+
+**Q: Gehen meine Daten verloren wenn ich den Server wechsle?**  
+A: Nein! Erstelle ein lokales Backup, wechsle Server, stelle wieder her.
+
+**Q: Warum JSON + Markdown?**  
+A: JSON ist zuverlässig und schnell (Master). Markdown ist menschenlesbar (Mirror für Desktop).
+
+**Q: Kann ich die App ohne Google Play nutzen?**  
+A: Ja! Lade die APK direkt von GitHub oder nutze F-Droid.
+
+---
+
+**Letzte Aktualisierung:** v1.3.2 (2026-01-10)

fastlane/metadata/android/de-DE/changelogs/10.txt

@@ -0,0 +1,5 @@
+Unter der Haube haben wir ordentlich aufgeraumt:
+- Verbesserte Sync-Performance durch optimierten Code
+- Stabilere Fehlerbehandlung bei Verbindungsproblemen
+- Speichereffizientere Datenverarbeitung
+- Datenschutz-Hinweis fur Datei-Logging hinzugefugt

fastlane/metadata/android/de-DE/changelogs/5.txt

@@ -0,0 +1,13 @@
+v1.2.0 - Backup & Desktop-Integration
+
+Lokales Backup/Restore
+• Exportiere alle Notizen als JSON
+• 3 Wiederherstellungs-Modi (Merge/Replace/Overwrite)
+• Auto-Backup vor Restore
+
+Markdown Desktop-Integration (optional)
+• .md Export für Desktop-Editoren (WebDAV-Mount)
+• Last-Write-Wins Sync
+• Manueller Import
+
+Sync-Architektur Doku

fastlane/metadata/android/de-DE/changelogs/6.txt

@@ -0,0 +1,12 @@
+v1.2.1 - Initial Export + URL Normalization
+
+Fehlerbehebung
+• Bestehende Notizen werden beim Aktivieren der Desktop-Integration exportiert
+• Markdown-Dateien landen korrekt im /notes-md/ Ordner
+• Vereinfachte Server-Konfiguration: Nur Base-URL eingeben (z.B. http://server:8080/)
+• App erstellt automatisch /notes/ und /notes-md/
+• Beide URL-Varianten funktionieren: mit und ohne /notes
+
+Verbesserungen
+• Beispiel-URL zeigt jetzt /notes statt /webdav
+• Progress-Dialog beim Export

fastlane/metadata/android/de-DE/changelogs/7.txt

@@ -0,0 +1,12 @@
+v1.2.2 - Rückwärtskompatibilität für v1.2.0 User
+
+Kritische Fehlerbehebung
+• Server-Wiederherstellung findet jetzt ALLE Notizen (Root + /notes/)
+• User die von v1.2.0 upgraden verlieren keine Daten mehr
+• Alte Notizen aus Root-Ordner werden beim Restore gefunden
+
+Technische Details
+• Dual-Mode Download nur bei Server-Restore aktiv
+• Normale Syncs bleiben schnell (scannen nur /notes/)
+• Automatische Deduplication verhindert Duplikate
+• Sanfte Migration: Neue Uploads gehen in /notes/, alte bleiben lesbar

fastlane/metadata/android/de-DE/changelogs/8.txt

@@ -0,0 +1,12 @@
+v1.3.0 - Multi-Device Sync
+
+NEUE FEATURES:
+• Multi-Device Sync mit Deletion Tracking (keine Zombie-Notizen)
+• Wisch-Geste zum Server-Löschen (verhindert Duplikate auf anderen Geräten)
+• E-Tag Performance-Optimierung (~150ms statt 3s)
+• Markdown Auto-Sync Toggle (Export + Import vereint)
+• Manueller Markdown-Sync Button
+• Server-Wiederherstellung Modi (Merge/Replace/Overwrite)
+
+Dank an Thomas aus Bielefeld!
+Kompatibel: v1.2.0-v1.3.0

fastlane/metadata/android/de-DE/changelogs/9.txt

@@ -0,0 +1,13 @@
+v1.3.1 - Multi-Device Sync Fix + Performance
+
+Multi-Device JSON Sync (Danke Thomas!):
+- JSON-Dateien syncen jetzt zwischen Geräten
+- Funktioniert auch ohne Markdown aktiviert
+- Keine doppelten Downloads mehr
+
+Performance-Verbesserungen:
+- Sync beschleunigt: 12-14s -> 2-3s
+- Erster Sync nach MD-Export jetzt schnell
+- JSON erreicht Markdown-Geschwindigkeit
+
++ Sync-Status-UI, Content MD-Import, Debug-Tools

fastlane/metadata/android/de-DE/full_description.txt

@@ -4,12 +4,14 @@ HAUPTFUNKTIONEN:
 
 • Einfache Notizen erstellen und bearbeiten
 • WebDAV-Synchronisation mit eigenem Server
+• Multi-Device Sync (Handy, Tablet, Desktop)
+• Markdown-Export für Obsidian/Desktop-Editoren
 • Automatische Synchronisation im Heim-WLAN
 • Konfigurierbares Sync-Interval (15/30/60 Minuten)
 • Transparente Batterie-Verbrauchsanzeige
 • Material Design 3 mit Dynamic Colors (Android 12+)
-• Swipe-to-Delete mit Bestätigungsdialog
-• Server-Backup & Wiederherstellung
+• Swipe-to-Delete mit Server-Sync
+• Server-Backup & Wiederherstellung (Merge/Replace/Overwrite)
 • Komplett offline nutzbar
 • Keine Werbung, keine Tracker
 
@@ -17,14 +19,23 @@ DATENSCHUTZ:
 
 Deine Daten bleiben bei dir! Die App kommuniziert nur mit deinem eigenen WebDAV-Server. Keine Cloud-Dienste, keine Tracking-Bibliotheken, keine Analysetools.
 
+MULTI-DEVICE SYNC:
+
+• Notizen synchronisieren automatisch zwischen allen Geräten
+• Lösch-Tracking verhindert "Zombie-Notizen"
+• Intelligente Konfliktlösung durch Timestamps
+• Markdown-Dateien für Desktop-Bearbeitung (Obsidian, VS Code, etc.)
+• Änderungen von Desktop-Editoren werden automatisch importiert
+
 SYNCHRONISATION:
 
 • Unterstützt alle WebDAV-Server (Nextcloud, ownCloud, etc.)
 • Konfigurierbares Interval: 15, 30 oder 60 Minuten
+• Optimierte Performance: überspringt unveränderte Dateien (~2-3s Sync-Zeit)
+• E-Tag Caching für 20x schnellere "keine Änderungen" Checks
 • Gemessener Akkuverbrauch: nur ~0.4% pro Tag (bei 30min)
 • Doze Mode optimiert für zuverlässige Background-Syncs
 • Manuelle Synchronisation jederzeit möglich
-• Konfliktfreie Zusammenführung durch Timestamps
 
 MATERIAL DESIGN 3:
 
@@ -32,6 +43,7 @@ MATERIAL DESIGN 3:
 • Dynamic Colors (Material You) auf Android 12+
 • Dark Mode Support
 • Intuitive Gesten (Swipe-to-Delete)
+• Live Sync-Status Anzeige
 
 Open Source unter MIT-Lizenz
 Quellcode: https://github.com/inventory69/simple-notes-sync

fastlane/metadata/android/en-US/changelogs/10.txt

@@ -0,0 +1,5 @@
+Under the hood improvements:
+- Improved sync performance through optimized code
+- More stable error handling for connection issues
+- More memory-efficient data processing
+- Added privacy notice for file logging

fastlane/metadata/android/en-US/changelogs/5.txt

@@ -0,0 +1,13 @@
+v1.2.0 - Backup & Desktop Integration
+
+Local Backup/Restore
+• Export all notes as JSON
+• 3 restore modes (Merge/Replace/Overwrite)
+• Auto-backup before restore
+
+Markdown Desktop Integration (optional)
+• .md export for desktop editors (WebDAV mount)
+• Last-Write-Wins sync
+• Manual import
+
+Sync architecture docs

fastlane/metadata/android/en-US/changelogs/6.txt

@@ -0,0 +1,12 @@
+v1.2.1 - Initial Export + URL Normalization
+
+Bugfixes
+• Existing notes are now exported when Desktop Integration is enabled
+• Markdown files now correctly land in /notes-md/ folder
+• Simplified server config: Enter only base URL (e.g. http://server:8080/)
+• App automatically creates /notes/ and /notes-md/
+• Both URL variants work: with and without /notes
+
+Improvements
+• Example URL now shows /notes instead of /webdav
+• Progress dialog during export

fastlane/metadata/android/en-US/changelogs/7.txt

@@ -0,0 +1,12 @@
+v1.2.2 - Backward Compatibility for v1.2.0 Users
+
+Critical Bugfix
+• Server restore now finds ALL notes (Root + /notes/)
+• Users upgrading from v1.2.0 no longer lose data
+• Old notes from Root folder are found during restore
+
+Technical Details
+• Dual-mode download only active for server restore
+• Normal syncs remain fast (scan only /notes/)
+• Automatic deduplication prevents duplicates
+• Smooth migration: New uploads go to /notes/, old ones remain readable

fastlane/metadata/android/en-US/changelogs/8.txt

@@ -0,0 +1,12 @@
+v1.3.0 - Multi-Device Sync
+
+NEW FEATURES:
+• Multi-Device Sync with deletion tracking (no zombie notes)
+• Swipe gesture for server deletion (prevents duplicates on other devices)
+• E-Tag performance optimization (~150ms vs 3s)
+• Markdown Auto-Sync toggle (unified Export + Import)
+• Manual Markdown sync button
+• Server restore modes (Merge/Replace/Overwrite)
+
+Thanks to Thomas from Bielefeld!
+Compatible: v1.2.0-v1.3.0

fastlane/metadata/android/en-US/changelogs/9.txt

@@ -0,0 +1,13 @@
+v1.3.1 - Multi-Device Sync Fix + Performance
+
+Multi-Device JSON Sync (Thanks Thomas!):
+- JSON files now sync between devices
+- Works without Markdown enabled
+- No duplicate downloads anymore
+
+Performance Improvements:
+- Sync speed: 12-14s -> 2-3s
+- First sync after MD export now fast
+- JSON matches Markdown speed
+
++ Sync status UI, content MD import, debug tools

fastlane/metadata/android/en-US/full_description.txt

@@ -4,12 +4,14 @@ KEY FEATURES:
 
 • Create and edit simple notes
 • WebDAV synchronization with your own server
+• Multi-device sync (phone, tablet, desktop)
+• Markdown export for Obsidian/desktop editors
 • Automatic synchronization on home WiFi
 • Configurable sync interval (15/30/60 minutes)
 • Transparent battery usage display
 • Material Design 3 with Dynamic Colors (Android 12+)
-• Swipe-to-delete with confirmation dialog
-• Server backup & restore
+• Swipe-to-delete with server sync
+• Server backup & restore (Merge/Replace/Overwrite)
 • Fully usable offline
 • No ads, no trackers
 
@@ -17,14 +19,23 @@ PRIVACY:
 
 Your data stays with you! The app only communicates with your own WebDAV server. No cloud services, no tracking libraries, no analytics tools.
 
+MULTI-DEVICE SYNC:
+
+• Notes sync automatically between all your devices
+• Deletion tracking prevents "zombie notes"
+• Smart conflict resolution through timestamps
+• Markdown files for desktop editing (Obsidian, VS Code, etc.)
+• Changes from desktop editors are auto-imported
+
 SYNCHRONIZATION:
 
 • Supports all WebDAV servers (Nextcloud, ownCloud, etc.)
 • Configurable interval: 15, 30, or 60 minutes
+• Optimized performance: skips unchanged files (~2-3s sync time)
+• E-Tag caching for 20x faster "no changes" checks
 • Measured battery consumption: only ~0.4% per day (at 30min)
 • Doze Mode optimized for reliable background syncs
 • Manual synchronization available anytime
-• Conflict-free merging through timestamps
 
 MATERIAL DESIGN 3:
 
@@ -32,6 +43,7 @@ MATERIAL DESIGN 3:
 • Dynamic Colors (Material You) on Android 12+
 • Dark Mode support
 • Intuitive gestures (Swipe-to-delete)
+• Live sync status indicator
 
 Open Source under MIT License
 Source code: https://github.com/inventory69/simple-notes-sync

metadata/dev.dettmer.simplenotes.yml

@@ -1,8 +1,8 @@
 Categories:
   - Writing
 License: MIT
-AuthorName: Liq Dettmer
-AuthorEmail: liq@dettmer.dev
+AuthorName: inventory69
+AuthorEmail: admin@dettmer.dev
 AuthorWebSite: https://dettmer.dev
 SourceCode: https://github.com/inventory69/simple-notes-sync
 IssueTracker: https://github.com/inventory69/simple-notes-sync/issues
@@ -47,7 +47,79 @@ Builds:
     scandelete:
       - android/gradle/wrapper
 
+  - versionName: 1.2.0
+    versionCode: 5
+    commit: v1.2.0
+    subdir: android/app
+    sudo:
+      - apt-get update
+      - apt-get install -y openjdk-17-jdk-headless
+      - update-java-alternatives -a
+    gradle:
+      - fdroid
+    srclibs:
+      - reproducible-apk-tools@v0.2.8
+    prebuild: sed -i -e '/signingConfig/d' build.gradle.kts
+    scandelete:
+      - android/gradle/wrapper
+
+  - versionName: 1.2.1
+    versionCode: 6
+    commit: v1.2.1
+    subdir: android/app
+    sudo:
+      - apt-get update
+      - apt-get install -y openjdk-17-jdk-headless
+      - update-java-alternatives -a
+    gradle:
+      - fdroid
+    prebuild: sed -i -e '/signingConfig/d' build.gradle.kts
+    scandelete:
+      - android/gradle/wrapper
+
+  - versionName: 1.2.2
+    versionCode: 7
+    commit: v1.2.2
+    subdir: android/app
+    sudo:
+      - apt-get update
+      - apt-get install -y openjdk-17-jdk-headless
+      - update-java-alternatives -a
+    gradle:
+      - fdroid
+    prebuild: sed -i -e '/signingConfig/d' build.gradle.kts
+    scandelete:
+      - android/gradle/wrapper
+
+  - versionName: 1.3.0
+    versionCode: 8
+    commit: v1.3.0
+    subdir: android/app
+    sudo:
+      - apt-get update
+      - apt-get install -y openjdk-17-jdk-headless
+      - update-java-alternatives -a
+    gradle:
+      - fdroid
+    prebuild: sed -i -e '/signingConfig/d' build.gradle.kts
+    scandelete:
+      - android/gradle/wrapper
+
+  - versionName: 1.3.1
+    versionCode: 9
+    commit: v1.3.1
+    subdir: android/app
+    sudo:
+      - apt-get update
+      - apt-get install -y openjdk-17-jdk-headless
+      - update-java-alternatives -a
+    gradle:
+      - fdroid
+    prebuild: sed -i -e '/signingConfig/d' build.gradle.kts
+    scandelete:
+      - android/gradle/wrapper
+
 AutoUpdateMode: Version
 UpdateCheckMode: Tags
-CurrentVersion: 1.1.1
-CurrentVersionCode: 3
+CurrentVersion: 1.3.1
+CurrentVersionCode: 9