Release v1.6.0: Configurable Sync Triggers + Offline Mode

- NEW: Configurable sync triggers (onSave, onResume, WiFi, Periodic, Boot)
- NEW: Offline mode toggle to disable all network features
- Various fixes and UI improvements
- Version bumped to 1.6.0 (code 14)

.gitignore

@@ -43,3 +43,8 @@ Thumbs.db
 *.swp
 *~
 test-apks/
+
+# F-Droid metadata (managed in fdroiddata repo)
+# Exclude fastlane metadata (we want to track those screenshots)
+metadata/
+!fastlane/metadata/