fix(flywheel): 四階段系統性修復 AUTO_REPAIR NO_MATCH 斷層

Phase 1 — affected_services 污染根治
  - webhooks.py: _extract_affected_services() 從 labels 精準萃取服務名
    (component > job > pod deployment name > clean target_resource > [])
  - create_incident_for_approval: alert_labels 完整保留進 Signal
  - alert_name 從 alertname 取，不再用 "custom"

Phase 2 — Playbook alertname 變體擴充
  - alert_rules.yaml: 5 條規則新增 HostHighCpuLoad、KubePodCrashLooping 等變體
  - scripts/update_playbook_alert_variants.py: Redis index 已執行更新 ✅

Phase 3 — Jaccard 通用型 Playbook 豁免
  - similarity.py: affected_services=[] → 1.0 豁免（基礎設施 Playbook 不針對特定服務）
  - severity_range=[] → 1.0 豁免（適用所有嚴重度）

Phase 4 — Playbook Embedding 持久化（冷啟動修復）
  - migrations/flywheel_playbook_embeddings.sql: pgvector 持久化表
  - services/playbook_embedding_service.py: 啟動時重建 Redis 向量快取 + 同步 DB
  - main.py: lifespan 啟動時 asyncio.create_task 非阻塞執行

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

@@ -0,0 +1,126 @@
+"""
+Playbook Embedding Service — Phase 4 飛輪冷啟動修復
+====================================================
+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
+"""
+
+from __future__ import annotations
+
+import structlog
+
+logger = structlog.get_logger(__name__)
+
+
+async def ensure_playbook_embeddings_indexed() -> None:
+    """
+    確保所有 APPROVED Playbooks 都有向量索引。
+
+    執行步驟:
+    1. 從 PlaybookService 取得所有 APPROVED Playbooks
+    2. 呼叫 PlaybookRAGService.reindex_all_playbooks → 更新 Redis 向量快取
+    3. 將向量持久化到 playbook_embeddings (pgvector) 表
+    """
+    try:
+        from src.models.playbook import PlaybookStatus
+        from src.services.playbook_service import get_playbook_service
+        from src.services.playbook_rag import get_playbook_rag_service
+
+        playbook_service = get_playbook_service()
+        playbooks, total = await playbook_service.list_playbooks(
+            status=PlaybookStatus.APPROVED, limit=500
+        )
+
+        if not playbooks:
+            logger.info("playbook_embedding_indexing_skipped", reason="no approved playbooks")
+            return
+
+        logger.info("playbook_embedding_indexing_start", count=len(playbooks))
+
+        # Step 1: 重建 Redis 向量快取 (現有邏輯)
+        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,
+        )
+
+        # Step 2: 持久化到 PostgreSQL playbook_embeddings 表
+        await _persist_embeddings_to_db(rag_service, playbooks)
+
+    except Exception as e:
+        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)。"""
+    try:
+        from sqlalchemy import text
+        from src.db.base import get_db_context
+
+        persisted = 0
+        skipped = 0
+
+        async with get_db_context() as db:
+            for playbook in playbooks:
+                try:
+                    embedding = await rag_service.get_playbook_embedding(playbook.playbook_id)
+                    if not embedding:
+                        skipped += 1
+                        continue
+
+                    sp = playbook.symptom_pattern
+                    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,
+                        },
+                    )
+                    persisted += 1
+
+                except Exception as e:
+                    logger.warning(
+                        "playbook_embedding_persist_error",
+                        playbook_id=playbook.playbook_id,
+                        error=str(e),
+                    )
+                    skipped += 1
+
+            await db.commit()
+
+        logger.info(
+            "playbook_embedding_db_done",
+            persisted=persisted,
+            skipped=skipped,
+        )
+
+    except Exception as e:
+        logger.warning("playbook_embedding_db_error", error=str(e))