Merge pull request #4 from inventory69/release/v1.3.0

Release v1.3.0: Multi-Device Sync

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

@@ -104,24 +104,22 @@ jobs:
       
       - name: F-Droid Changelogs lesen
         run: |
-          # Lese deutsche Changelog (Hauptsprache)
+          # Lese deutsche Changelog (Hauptsprache) - Use printf to ensure proper formatting
-          if [ -f "android/fastlane/metadata/android/de-DE/changelogs/${{ env.BUILD_NUMBER }}.txt" ]; then
+          if [ -f "fastlane/metadata/android/de-DE/changelogs/${{ env.BUILD_NUMBER }}.txt" ]; then
-            {
+            CHANGELOG_CONTENT=$(cat "fastlane/metadata/android/de-DE/changelogs/${{ env.BUILD_NUMBER }}.txt")
-              echo 'CHANGELOG_DE<<EOF'
+            echo "CHANGELOG_DE<<GHADELIMITER" >> $GITHUB_ENV
-              cat "android/fastlane/metadata/android/de-DE/changelogs/${{ env.BUILD_NUMBER }}.txt"
+            echo "$CHANGELOG_CONTENT" >> $GITHUB_ENV
-              echo 'EOF'
+            echo "GHADELIMITER" >> $GITHUB_ENV
-            } >> $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/${{ env.BUILD_NUMBER }}.txt" ]; then
+          if [ -f "fastlane/metadata/android/en-US/changelogs/${{ env.BUILD_NUMBER }}.txt" ]; then
-            {
+            CHANGELOG_CONTENT_EN=$(cat "fastlane/metadata/android/en-US/changelogs/${{ env.BUILD_NUMBER }}.txt")
-              echo 'CHANGELOG_EN<<EOF'
+            echo "CHANGELOG_EN<<GHADELIMITER" >> $GITHUB_ENV
-              cat "android/fastlane/metadata/android/en-US/changelogs/${{ env.BUILD_NUMBER }}.txt"
+            echo "$CHANGELOG_CONTENT_EN" >> $GITHUB_ENV
-              echo 'EOF'
+            echo "GHADELIMITER" >> $GITHUB_ENV
-            } >> $GITHUB_ENV
           else
             echo "CHANGELOG_EN=" >> $GITHUB_ENV
           fi
@@ -153,12 +151,12 @@ jobs:
             
             ## 📋 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 +1,263 @@
+# 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/).
+
+---
+
+## [1.3.0] - 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
+- 📝 **Offline-first** - Works without internet
-- Create and edit simple text notes
+- 🔄 **Auto-sync** - Home WiFi only (15/30/60 min)
-- Automatic save
+- 🔒 **Self-hosted** - Your data stays with you (WebDAV)
-- Swipe-to-delete with confirmation
+- 💾 **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
+➡️ **Complete feature list:** [FEATURES.en.md](docs/FEATURES.en.md)
-- 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
 
 ---
 
 ## 🚀 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
+3. ⚙️ Settings → Configure server:
-4. Enable auto-sync
+   - **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
+| Document | Content |
-- **[Server Setup](server/README.en.md)** - Configure WebDAV server
+|----------|---------|
-- **[Complete Docs](DOCS.en.md)** - Features, troubleshooting, build instructions
+| **[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)
 
 ---
 
 ## 🤝 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
+---
+
+**v1.2.1** · 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
+- 📝 **Offline-First** - Funktioniert ohne Internet
-- Einfache Textnotizen erstellen und bearbeiten
+- 🔄 **Auto-Sync** - Nur im Heim-WLAN (15/30/60 Min)
-- Automatisches Speichern
+- 🔒 **Self-Hosted** - Deine Daten bleiben bei dir (WebDAV)
-- Swipe-to-Delete mit Bestätigung
+- 💾 **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
+➡️ **Vollständige Feature-Liste:** [FEATURES.md](docs/FEATURES.md)
-- 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
 
 ---
 
-## 🚀 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
+3. ⚙️ Einstellungen → Server konfigurieren:
-4. Auto-Sync aktivieren
+   - **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
+| Dokument | Inhalt |
-- **[Server Setup](server/README.md)** - WebDAV Server konfigurieren
+|----------|--------|
-- **[Vollständige Docs](DOCS.md)** - Features, Troubleshooting, Build-Anleitung
+| **[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)
 
 ---
 
 ## 🤝 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
+---
+
+**v1.2.1** · Built with ❤️ using Kotlin + Material Design 3

android/app/build.gradle.kts

@@ -17,8 +17,8 @@ android {
         applicationId = "dev.dettmer.simplenotes"
         minSdk = 24
         targetSdk = 36
-        versionCode = 4  // 🔥 v1.1.2: UX Fixes + CancellationException Handling
+        versionCode = 8  // 🚀 v1.3.0: Multi-Device Sync with deletion tracking
-        versionName = "1.1.2"  // 🔥 v1.1.2: Better UX + Job Cancellation Fix
+        versionName = "1.3.0"  // 🚀 v1.3.0: Multi-Device Sync, E-Tag caching, Markdown auto-import
 
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
         

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

@@ -21,13 +21,19 @@ 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
@@ -320,36 +326,20 @@ class MainActivity : AppCompatActivity() {
             ): Boolean = false
             
             override fun onSwiped(viewHolder: RecyclerView.ViewHolder, direction: Int) {
-                val position = viewHolder.adapterPosition
+                val position = viewHolder.bindingAdapterPosition
-                val note = adapter.currentList[position]
+                val swipedNote = adapter.currentList[position]
-                val notesCopy = adapter.currentList.toMutableList()
                 
-                // Track pending deletion to prevent flicker
+                // Store original list BEFORE removing note
-                pendingDeletions.add(note.id)
+                val originalList = adapter.currentList.toList()
                 
-                // Remove from list immediately for visual feedback
+                // Remove from list for visual feedback (NOT from storage yet!)
-                notesCopy.removeAt(position)
+                val listWithoutNote = originalList.toMutableList().apply {
-                adapter.submitList(notesCopy)
+                    removeAt(position)
-                
-                // 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()
                 }
-                    }
+                adapter.submitList(listWithoutNote)
-                }).show()
+                
+                // Show dialog with ability to restore
+                showServerDeletionDialog(swipedNote, originalList)
             }
             
             override fun getSwipeThreshold(viewHolder: RecyclerView.ViewHolder): Float {
@@ -361,6 +351,104 @@ 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)

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
@@ -26,6 +29,8 @@ 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
@@ -53,10 +58,15 @@ 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 +83,22 @@ class SettingsActivity : AppCompatActivity() {
     private lateinit var cardDeveloperProfile: MaterialCardView
     private lateinit var cardLicense: MaterialCardView
     
+    // 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)
     }
@@ -106,10 +132,15 @@ 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)
@@ -153,6 +184,14 @@ 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 +262,35 @@ 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) {}
@@ -498,6 +557,103 @@ 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
@@ -612,4 +768,281 @@ 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 dialogView = layoutInflater.inflate(android.R.layout.select_dialog_singlechoice, null)
+        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 = 0
+            isChecked = true
+            setPadding(10, 10, 10, 10)
+        }
+        
+        val radioReplace = android.widget.RadioButton(this).apply {
+            text = "⚪ Ersetzen\n   → Alle löschen & Backup importieren"
+            id = 1
+            setPadding(10, 10, 10, 10)
+        }
+        
+        val radioOverwrite = android.widget.RadioButton(this).apply {
+            text = "⚪ Duplikate überschreiben\n   → Backup gewinnt bei Konflikten"
+            id = 2
+            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) {
+                    1 -> RestoreMode.REPLACE
+                    2 -> 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.imported_notes} Notizen"
+                    showToast("✅ $message")
+                    
+                    // Refresh MainActivity's note list
+                    setResult(RESULT_OK)
+                    broadcastNotesChanged(result.imported_notes)
+                } 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 +1,361 @@
+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(
+                backup_version = BACKUP_VERSION,
+                created_at = System.currentTimeMillis(),
+                notes_count = allNotes.size,
+                app_version = 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,
+                notes_count = 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(
+                backup_version = BACKUP_VERSION,
+                created_at = System.currentTimeMillis(),
+                notes_count = allNotes.size,
+                app_version = 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.notes_count} notes, version ${backupData.backup_version}")
+            
+            // 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.imported_notes} imported, ${result.skipped_notes} skipped")
+            result
+            
+        } catch (e: Exception) {
+            Logger.e(TAG, "Failed to restore backup", e)
+            RestoreResult(
+                success = false,
+                error = "Wiederherstellung fehlgeschlagen: ${e.message}"
+            )
+        }
+    }
+    
+    /**
+     * Validiert Backup-Datei
+     */
+    private fun validateBackup(jsonString: String): ValidationResult {
+        return try {
+            val backupData = gson.fromJson(jsonString, BackupData::class.java)
+            
+            // Version kompatibel?
+            if (backupData.backup_version > BACKUP_VERSION) {
+                return ValidationResult(
+                    isValid = false,
+                    errorMessage = "Backup-Version nicht unterstützt (v${backupData.backup_version} 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: ${e.message}"
+            )
+        }
+    }
+    
+    /**
+     * Restore-Modus: MERGE
+     * Fügt neue Notizen hinzu, behält bestehende
+     */
+    private fun restoreMerge(backupNotes: List<Note>): RestoreResult {
+        val existingNotes = storage.loadAllNotes()
+        val existingIds = existingNotes.map { it.id }.toSet()
+        
+        val newNotes = backupNotes.filter { it.id !in existingIds }
+        val skippedNotes = backupNotes.size - newNotes.size
+        
+        newNotes.forEach { note ->
+            storage.saveNote(note)
+        }
+        
+        return RestoreResult(
+            success = true,
+            imported_notes = newNotes.size,
+            skipped_notes = skippedNotes,
+            message = "${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,
+            imported_notes = backupNotes.size,
+            skipped_notes = 0,
+            message = "Alle Notizen ersetzt: ${backupNotes.size} importiert"
+        )
+    }
+    
+    /**
+     * Restore-Modus: OVERWRITE_DUPLICATES
+     * Backup überschreibt bei ID-Konflikten
+     */
+    private fun restoreOverwriteDuplicates(backupNotes: List<Note>): RestoreResult {
+        val existingNotes = storage.loadAllNotes()
+        val existingIds = existingNotes.map { it.id }.toSet()
+        
+        val newNotes = backupNotes.filter { it.id !in existingIds }
+        val overwrittenNotes = backupNotes.filter { it.id in existingIds }
+        
+        // Alle Backup-Notizen speichern (überschreibt automatisch)
+        backupNotes.forEach { note ->
+            storage.saveNote(note)
+        }
+        
+        return RestoreResult(
+            success = true,
+            imported_notes = newNotes.size,
+            skipped_notes = 0,
+            overwritten_notes = overwrittenNotes.size,
+            message = "${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)
+ */
+data class BackupData(
+    val backup_version: Int,
+    val created_at: Long,
+    val notes_count: Int,
+    val app_version: 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 notes_count: Int = 0,
+    val message: String? = null,
+    val error: String? = null
+)
+
+/**
+ * Restore-Ergebnis
+ */
+data class RestoreResult(
+    val success: Boolean,
+    val imported_notes: Int = 0,
+    val skipped_notes: Int = 0,
+    val overwritten_notes: 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 +1,77 @@
+package dev.dettmer.simplenotes.models
+
+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 {
+        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) {
+                null
+            }
+        }
+    }
+}

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

@@ -1,5 +1,9 @@
 package dev.dettmer.simplenotes.models
 
+import java.text.SimpleDateFormat
+import java.util.Date
+import java.util.Locale
+import java.util.TimeZone
 import java.util.UUID
 
 data class Note(
@@ -25,6 +29,25 @@ 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 {
         fun fromJson(json: String): Note? {
             return try {
@@ -34,6 +57,78 @@ data class Note(
                 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) {
+                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) {
+                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()
+            val notes = loadAllNotes()
-                ?.filter { it.extension == "json" }
+            val deviceId = DeviceIdGenerator.getDeviceId(context)
-                ?.forEach { it.delete() }
+            
+            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/utils/Constants.kt

@@ -19,6 +19,14 @@ 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"
+    
     // WorkManager
     const val SYNC_WORK_TAG = "notes_sync"
     const val SYNC_DELAY_SECONDS = 5L

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>

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>

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 +1,274 @@
+# 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)
+
+---
+
+## 🔋 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
+
+### 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 (see [TODO.md](project-docs/simple-notes-sync/planning/TODO.md)):
+
+### v1.3.0 - Web Editor & Organization
+- ⏳ **Browser-based editor** - Edit notes in web browser
+- ⏳ **WebDAV access via browser** - No mount needed
+- ⏳ **Mobile-optimized** - Responsive design
+- ⏳ **Offline-capable** - Progressive Web App (PWA)
+- ⏳ **Tags/labels** - Categorize notes
+- ⏳ **Search** - Full-text search in all notes
+- ⏳ **Sorting** - By date, title, tags
+- ⏳ **Filter** - Filter by tags
+
+### v1.4.0 - Sharing & Export
+- ⏳ **Share note** - Via share intent
+- ⏳ **Export single note** - As .txt or .md
+- ⏳ **Import from text** - Via share intent
+
+### v1.5.0 - Advanced Editor Features
+- ⏳ **Markdown preview** - In-app rendering
+- ⏳ **Checklists** - TODO lists in notes
+- ⏳ **Syntax highlighting** - For code snippets
+
+---
+
+## 📊 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:** v1.2.1 (2026-01-05)

docs/FEATURES.md

@@ -0,0 +1,274 @@
+# 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)
+
+---
+
+## 🔋 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
+
+### 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 (siehe [TODO.md](project-docs/simple-notes-sync/planning/TODO.md)):
+
+### v1.3.0 - Web Editor & Organisation
+- ⏳ **Browser-basierter Editor** - Notizen im Webbrowser bearbeiten
+- ⏳ **WebDAV-Zugriff via Browser** - Kein Mount nötig
+- ⏳ **Mobile-optimiert** - Responsive Design
+- ⏳ **Offline-fähig** - Progressive Web App (PWA)
+- ⏳ **Tags/Labels** - Kategorisierung von Notizen
+- ⏳ **Suche** - Volltextsuche in allen Notizen
+- ⏳ **Sortierung** - Nach Datum, Titel, Tags
+- ⏳ **Filter** - Nach Tags filtern
+
+### v1.4.0 - Sharing & Export
+- ⏳ **Notiz teilen** - Via Share-Intent
+- ⏳ **Einzelne Notiz exportieren** - Als .txt oder .md
+- ⏳ **Import von Text** - Via Share-Intent
+
+### v1.5.0 - Erweiterte Editor-Features
+- ⏳ **Markdown-Vorschau** - In-App Rendering
+- ⏳ **Checklisten** - TODO-Listen in Notizen
+- ⏳ **Syntax-Highlighting** - Für Code-Snippets
+
+---
+
+## 📊 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:** v1.2.1 (2026-01-05)

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/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

metadata/dev.dettmer.simplenotes.yml

@@ -47,7 +47,23 @@ 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
+
 AutoUpdateMode: Version
 UpdateCheckMode: Tags
-CurrentVersion: 1.1.1
+CurrentVersion: 1.2.0
-CurrentVersionCode: 3
+CurrentVersionCode: 5