Extracts the near-identical "Sync settings" UI duplicated across 5 apps
(todo, diet_guard_app, workout_app, wake_alarm/phone_app, home_inventory)
into a single tested package. Firebase sync (primary) + optional local
backup slot; GitHub mirror UI was dropped per kuhy's explicit decision
mid-build in favor of Firebase-only, so existing apps keep their local
GitHub code untouched, just disconnected from this shared screen.
100% line coverage, flutter analyze clean under very_good_analysis.
Generalized check_no_crdt_sync_override.sh to guard any utils git
dependency (crdt_sync, sync_settings_ui), not just crdt_sync by name.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KdSp6Nbrs9xvsWkCMDN9a1
