fix(km): backfill symptoms hash read column

apps/api/src/db/base.py

@@ -19,7 +19,8 @@ from contextlib import asynccontextmanager
 
 from fastapi import HTTPException
 from sqlalchemy import text
-from sqlalchemy.exc import DBAPIError, TimeoutError as SQLAlchemyTimeoutError
+from sqlalchemy.exc import DBAPIError
+from sqlalchemy.exc import TimeoutError as SQLAlchemyTimeoutError
 from sqlalchemy.ext.asyncio import (
     AsyncConnection,
     AsyncEngine,
@@ -450,12 +451,15 @@ async def _run_init_db_ddl(conn: AsyncConnection) -> None:
         # 2026-04-29 ogt + Claude Opus 4.7: M4 KMWriter 反查鏈 + 冪等補欄
         # CD #1115-1117 全 failure 根因：commit c22e5f33 加 ORM 欄位但無對應 ALTER
         #   錯誤：column "related_approval_id" of relation "knowledge_entries" does not exist
+        # 2026-07-09 Codex: 舊 prod schema 也可能缺 symptoms_hash，會讓 KM list/search
+        # 只剩 source-backed fallback；同一段補齊，避免正式 KM 看似歸零。
         # 補防禦性 ALTER（同 timeline_events 模式）+ 對應 index
         await conn.execute(
             text("""
             ALTER TABLE knowledge_entries
                 ADD COLUMN IF NOT EXISTS related_approval_id VARCHAR(64),
-                ADD COLUMN IF NOT EXISTS path_type VARCHAR(50);
+                ADD COLUMN IF NOT EXISTS path_type VARCHAR(50),
+                ADD COLUMN IF NOT EXISTS symptoms_hash VARCHAR;
             """)
         )
         # M3 冪等 unique index (incident_id + path_type)
@@ -470,6 +474,11 @@ async def _run_init_db_ddl(conn: AsyncConnection) -> None:
             "ON knowledge_entries(related_approval_id) "
             "WHERE related_approval_id IS NOT NULL;"
         ))
+        await conn.execute(text(
+            "CREATE INDEX IF NOT EXISTS ix_knowledge_symptoms_hash "
+            "ON knowledge_entries(symptoms_hash) "
+            "WHERE symptoms_hash IS NOT NULL;"
+        ))
 
         # W2 PR-L1 2026-04-28 ogt + Claude Sonnet 4.6: KM→Playbook 互饋回路（飛輪 C3 修復）
         # PlaybookRecord 新增 review_required 欄位

apps/api/tests/test_knowledge_repository_read_model.py

@@ -9,8 +9,8 @@ from sqlalchemy.dialects import postgresql
 from src.db.models import KnowledgeEntryRecord
 from src.models.knowledge import EntrySource, EntryStatus, EntryType
 from src.repositories.knowledge_repository import (
-    KnowledgeDBRepository,
     _ASSET_TAXONOMY_KEYS,
+    KnowledgeDBRepository,
     _enum_text,
 )
 

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