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
