Loose ends to finish the auth security round:
- register + password-reset-request had an enumeration TIMING oracle: an already-
registered email skipped the create path (hash + row writes + email scheduling) and
responded measurably faster than a new one. Move the whole lookup+create (register)
and lookup+token+email (reset) into a background task with its own DB session, so the
endpoint returns in the same time for any valid email regardless of whether it exists.
Verified: existing vs new now ~equal (was 34ms vs 82ms on register); accounts/tokens
still created off-path.
- messages_ws re-implemented resolved_user_id's per-tab wallet-gated account resolution.
Generalize resolved_user_id to take any HTTPConnection (Request OR WebSocket) and call
it from the WS — one shared, wallet-gated resolution. Behavior-identical (unit-checked).