Investigate offline support with TanStack SQLite persistence and offline transactions

[ivasilov]

What to build

Investigate the best supported path for using the Supabase collection adapter in offline-capable TanStack DB apps. This should use TanStack browser SQLite persistence and the TanStack offline transactions example as reference points.

The investigation should determine which pieces compose cleanly with this adapter today, which pieces need adapter changes, and which behaviors are constrained by Supabase Auth, RLS, PostgREST, or Realtime. The goal is not necessarily to deliver complete offline sync in one pass, but to produce examples or a clear design conclusion that users and maintainers can trust.

The completed issue should show the current best path for persisted collection data and offline mutation behavior. It should also document known limitations around queued writes, retry behavior, conflict handling, auth/session expiry, Realtime gaps, and multi-tab behavior.

Acceptance criteria

• Evaluate TanStack browser SQLite persistence with Supabase-backed collections.
• Evaluate TanStack offline transaction patterns with Supabase inserts, updates, and deletes.
• Produce a working example or document exactly why one is not currently possible.
• Document limitations around Auth, RLS, Realtime, conflicts, retries, and multi-tab behavior.
• Recommend follow-up adapter changes if needed.

Blocked by

None - can start immediately.