fix(db): await AsyncConnection.execution_options in run_maintenance

execution_options() is a coroutine on AsyncConnection and must be awaited;
the un-awaited call returned a coroutine, so exec_driver_sql() blew up with
AttributeError and every table's VACUUM was skipped (Run-now reported 0/6).
A prior change had wrongly dropped the await. Fix it and make the test mock
execution_options async so this call shape is actually exercised.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/scribe/services/db_maintenance.py

@@ -66,9 +66,10 @@ async def run_maintenance(tables: tuple[str, ...] | list[str] | None = None) ->
     results: list[dict] = []
 
     async with engine.connect() as conn:
-        # execution_options() is synchronous on AsyncConnection; it returns the
+        # On AsyncConnection, execution_options() is a coroutine and MUST be
-        # connection with AUTOCOMMIT set (VACUUM can't run in a transaction).
+        # awaited (it returns the connection with AUTOCOMMIT set — VACUUM can't
-        autocommit = conn.execution_options(isolation_level="AUTOCOMMIT")
+        # run inside a transaction block).
+        autocommit = await conn.execution_options(isolation_level="AUTOCOMMIT")
         for table in targets:
             t0 = time.monotonic()
             try:

tests/test_services_db_maintenance.py

@@ -16,7 +16,9 @@ def _mock_engine(exec_side_effect=None):
     conn = MagicMock()
     autocommit = MagicMock()
     autocommit.exec_driver_sql = AsyncMock(side_effect=exec_side_effect)
-    conn.execution_options.return_value = autocommit  # sync on AsyncConnection
+    # On AsyncConnection, execution_options() is a coroutine — mock it as async
+    # so the test exercises the real (awaited) call shape.
+    conn.execution_options = AsyncMock(return_value=autocommit)
     cm = AsyncMock()
     cm.__aenter__ = AsyncMock(return_value=conn)
     cm.__aexit__ = AsyncMock(return_value=False)
@@ -36,9 +38,9 @@ async def test_vacuums_each_allowlisted_table_once():
     assert issued == [f"VACUUM (ANALYZE) {t}" for t in MAINTENANCE_TABLES]
     assert all(r["ok"] for r in summary["tables"])
     assert len(summary["tables"]) == len(MAINTENANCE_TABLES)
-    # AUTOCOMMIT was requested — VACUUM cannot run inside a transaction.
+    # AUTOCOMMIT was requested (and awaited) — VACUUM can't run in a transaction.
     conn = engine.connect.return_value.__aenter__.return_value
-    conn.execution_options.assert_called_once_with(isolation_level="AUTOCOMMIT")
+    conn.execution_options.assert_awaited_once_with(isolation_level="AUTOCOMMIT")
 
 
 @pytest.mark.asyncio