- Single-object pooler API responses default to transaction-mode at 6543,
but the shared pooler tenant on new projects only listens on session/5432
- Add a `pool_mode == transaction && db_port == 6543` rewrite + stderr note
- Escape hatch via `GSTACK_SUPABASE_TRUST_API_PORT=1` for forward-compat
- 5 new tests covering rewrite, no-op shapes, env opt-out, array path
Fixes#1301.