Release v1.3.0: Multi-Device Sync with Deletion Tracking

New Features:
- Multi-Device Sync with deletion tracking (prevents zombie notes)
- Server deletion via swipe gesture with confirmation dialog
- E-Tag performance optimization (~150ms vs 3s for no-change syncs)
- Markdown Auto-Sync toggle (unified Export + Auto-Import)
- Manual Markdown sync button for performance control
- Server-Restore modes (Merge/Replace/Overwrite)

Technical Implementation:
- DeletionTracker model with JSON persistence
- Intelligent server checks with E-Tag caching
- Deletion-aware download logic
- Two-stage swipe deletion with Material Design dialog
- Automatic Markdown import during sync
- YAML frontmatter scanning for robust file deletion

Thanks to Thomas from Bielefeld for reporting the multi-device sync issue!

Compatible with: v1.2.0-v1.3.0

README.md

@@ -6,6 +6,8 @@
 [![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)
 
+[<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)