refactor(flywheel): 首席架構師審查修正 C1/C2/I1/I2/I3/I4/M1

C1 — Repository 層修正 (積木化鐵律):
  新增 PlaybookEmbeddingRepository (pgvector UPSERT)
  playbook_embedding_service 改透過 Repository 存取 DB，不再直接 db.execute(text(...))

C2 — Router 層業務邏輯移入 Service 層:
  create_incident_for_approval + extract_affected_services (去掉底線前綴) 移入 incident_service.py
  webhooks.py 改從 incident_service import，自身不再含業務邏輯

I1 — _infra_jobs 提升為 module-level frozenset (_INFRA_JOB_NAMES)，避免每次呼叫重建

I2 — _persist_embeddings_to_db 補齊 PlaybookRAGService / list[Playbook] 型別標注

I3 — embedding 格式顯式化: "[" + ",".join(str(float(x)) for x in embedding) + "]"
  防止 pgvector 因格式差異靜默解析失敗

I4 — import asyncio 移至 main.py 頂層，移除 try 區塊內重複 import

M1 — similarity.py: 移除死代碼 `if union > 0 else 0.0`
  union 在兩個集合都非空時不可能為 0

2026-04-10 Asia/Taipei — Claude Sonnet 4.6
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/api/src/services/playbook_embedding_service.py

@@ -6,17 +6,26 @@ ADR-067 延伸: Playbook 向量持久化到 PostgreSQL playbook_embeddings 表
 職責:
   - 啟動時掃描 APPROVED Playbooks，重建 Redis 向量快取
   - 同步持久化到 playbook_embeddings (pgvector) 供跨重啟使用
-  - 已索引且未變更的 Playbook 跳過 (updated_at 比對)
 
 呼叫方: main.py lifespan (asyncio.create_task — 非阻塞)
 
 2026-04-10 Claude Sonnet 4.6 Asia/Taipei
+修正 (首席架構師審查 2026-04-10):
+  C1: _persist_embeddings_to_db 改用 PlaybookEmbeddingRepository (積木化修復)
+  I2: 補齊 _persist_embeddings_to_db 型別標注
+  I3: embedding 格式顯式格式化，防止 pgvector 解析錯誤
 """
 
 from __future__ import annotations
 
+from typing import TYPE_CHECKING
+
 import structlog
 
+if TYPE_CHECKING:
+    from src.models.playbook import Playbook
+    from src.services.playbook_rag import PlaybookRAGService
+
 logger = structlog.get_logger(__name__)
 
 
@@ -35,7 +44,7 @@ async def ensure_playbook_embeddings_indexed() -> None:
         from src.services.playbook_rag import get_playbook_rag_service
 
         playbook_service = get_playbook_service()
-        playbooks, total = await playbook_service.list_playbooks(
+        playbooks, _total = await playbook_service.list_playbooks(
             status=PlaybookStatus.APPROVED, limit=500
         )
 
@@ -45,15 +54,11 @@ async def ensure_playbook_embeddings_indexed() -> None:
 
         logger.info("playbook_embedding_indexing_start", count=len(playbooks))
 
-        # Step 1: 重建 Redis 向量快取 (現有邏輯)
+        # Step 1: 重建 Redis 向量快取
         rag_service = await get_playbook_rag_service()
         success, failed = await rag_service.reindex_all_playbooks(playbooks)
 
-        logger.info(
-            "playbook_embedding_redis_done",
-            success=success,
-            failed=failed,
-        )
+        logger.info("playbook_embedding_redis_done", success=success, failed=failed)
 
         # Step 2: 持久化到 PostgreSQL playbook_embeddings 表
         await _persist_embeddings_to_db(rag_service, playbooks)
@@ -62,16 +67,26 @@ async def ensure_playbook_embeddings_indexed() -> None:
         logger.warning("playbook_embedding_indexing_error", error=str(e))
 
 
-async def _persist_embeddings_to_db(rag_service, playbooks) -> None:
-    """將 Redis 向量快取同步寫入 playbook_embeddings DB 表 (持久化層)。"""
+async def _persist_embeddings_to_db(
+    rag_service: "PlaybookRAGService",
+    playbooks: "list[Playbook]",
+) -> None:
+    """
+    將 Redis 向量快取同步寫入 playbook_embeddings DB 表 (持久化層)。
+
+    C1 修正: 改用 PlaybookEmbeddingRepository，Service 不直接操作 SQL。
+    I3 修正: embedding 格式由 Repository 層統一處理，防止 pgvector 解析錯誤。
+    """
     try:
-        from sqlalchemy import text
         from src.db.base import get_db_context
+        from src.repositories.playbook_embedding_repository import PlaybookEmbeddingRepository
 
         persisted = 0
         skipped = 0
 
         async with get_db_context() as db:
+            repo = PlaybookEmbeddingRepository(db)
+
             for playbook in playbooks:
                 try:
                     embedding = await rag_service.get_playbook_embedding(playbook.playbook_id)
@@ -83,28 +98,16 @@ async def _persist_embeddings_to_db(rag_service, playbooks) -> None:
                     alert_names = list(sp.alert_names) if sp else []
                     keywords = list(sp.keywords) if sp else []
 
-                    # UPSERT: 已存在則更新向量快照
-                    await db.execute(
-                        text("""
-                            INSERT INTO playbook_embeddings
-                                (playbook_id, embedding, alert_names, keywords, indexed_at, updated_at)
-                            VALUES
-                                (:playbook_id, :embedding, :alert_names, :keywords,
-                                 NOW(), NOW())
-                            ON CONFLICT (playbook_id) DO UPDATE SET
-                                embedding    = EXCLUDED.embedding,
-                                alert_names  = EXCLUDED.alert_names,
-                                keywords     = EXCLUDED.keywords,
-                                updated_at   = NOW()
-                        """),
-                        {
-                            "playbook_id": playbook.playbook_id,
-                            "embedding": str(embedding),  # pgvector accepts '[x,y,...]' string
-                            "alert_names": alert_names,
-                            "keywords": keywords,
-                        },
+                    ok = await repo.upsert(
+                        playbook_id=playbook.playbook_id,
+                        embedding=embedding,
+                        alert_names=alert_names,
+                        keywords=keywords,
                     )
-                    persisted += 1
+                    if ok:
+                        persisted += 1
+                    else:
+                        skipped += 1
 
                 except Exception as e:
                     logger.warning(
@@ -116,11 +119,7 @@ async def _persist_embeddings_to_db(rag_service, playbooks) -> None:
 
             await db.commit()
 
-        logger.info(
-            "playbook_embedding_db_done",
-            persisted=persisted,
-            skipped=skipped,
-        )
+        logger.info("playbook_embedding_db_done", persisted=persisted, skipped=skipped)
 
     except Exception as e:
         logger.warning("playbook_embedding_db_error", error=str(e))