Splits the old single Settings screen into two: "Enable advanced" plus
links to a Sync settings route (Firebase + notes backup, now the shared
sync_settings_ui package used across every kuhy app that syncs) and an
Advanced sync (GitHub) route. GitHub stays app-local rather than moving
into the shared package: connecting it here also triggers a real note sync
via runSync(), not just a settings save, which the generic package
intentionally doesn't do for any app.
313/313 tests passing, 100% line coverage on both new/changed screens,
flutter analyze clean.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KdSp6Nbrs9xvsWkCMDN9a1
