Adds 8 synchronous psycopg2-based tests that connect as resolutionflow_app
and verify the tenant_isolation RLS policies (USING + WITH CHECK) on the two
new L1 Phase 1 tables block cross-tenant reads and reject cross-tenant INSERTs.
Uses psycopg2 (not asyncpg) to avoid the conftest pytest_runtest_teardown hook
that closes the asyncio event loop after every test — incompatible with
module-scoped asyncpg fixtures in pytest-asyncio 0.24.
conftest.py: extends _RLS_TEST_FILES set to include test_l1_rls.py so it is
excluded from the default create_all test suite (requires RUN_RLS_TESTS=1).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
