fix(km): backfill symptoms hash read column

apps/api/tests/test_runtime_bootstrap_guards.py

@@ -255,3 +255,16 @@ def test_api_lifespan_closes_worker_redis_pool_after_signal_worker() -> None:
     assert "close_worker_redis_pool" in source
     assert source.index("close_signal_worker") < source.index("close_worker_redis_pool")
     assert source.index("close_worker_redis_pool") < source.index("close_redis_pool")
+
+
+def test_init_db_backfills_all_optional_knowledge_read_columns() -> None:
+    import inspect
+
+    from src.db import base as db_base
+
+    source = inspect.getsource(db_base._run_init_db_ddl)
+    assert "ALTER TABLE knowledge_entries" in source
+    assert "ADD COLUMN IF NOT EXISTS related_approval_id" in source
+    assert "ADD COLUMN IF NOT EXISTS path_type" in source
+    assert "ADD COLUMN IF NOT EXISTS symptoms_hash" in source
+    assert "CREATE INDEX IF NOT EXISTS ix_knowledge_symptoms_hash" in source