feat(api): Phase 16 R1.3 IncidentEngine 絞殺者模式

新增:
- IncidentMemoryAdapter: 實作 IIncidentMemory Protocol
- BlastRadiusAdapter: 實作 IBlastRadiusAnalyzer Protocol
- get_incident_engine() 雙軌切換 (USE_NEW_ENGINE)

絞殺者模式設計:
- 預設 USE_NEW_ENGINE=false (使用內嵌版)
- 設為 true 時使用 lewooogo-brain IncidentEngine
- 回滾: kubectl set env deployment/awoooi-api USE_NEW_ENGINE=false

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/api/src/services/incident_engine.py

@@ -593,7 +593,8 @@ class IncidentEngine:
         # 修復可能被轉成空物件的陣列欄位
         array_fields = ["signals", "affected_services", "proposal_ids"]
         for field in array_fields:
-            if field in data and isinstance(data[field], dict) and len(data[field]) == 0:
+            is_empty_dict = isinstance(data[field], dict) and len(data[field]) == 0
+            if field in data and is_empty_dict:
                 data[field] = []
 
         return Incident.model_validate(data)
@@ -643,15 +644,175 @@ class IncidentEngine:
 
 
 # =============================================================================
-# Singleton
+# Phase 16: 絞殺者模式 - Adapter 實作
+# =============================================================================
+
+class IncidentMemoryAdapter:
+    """
+    Incident Memory Adapter - 實作 lewooogo-brain 的 IIncidentMemory Protocol
+
+    Phase 16 R1.3: 橋接現有 Lua Scripts + DualIncidentMemory 到新 IncidentEngine
+
+    版本: v1.0
+    建立: 2026-03-26 (台北時區)
+    建立者: Claude Code
+    """
+
+    def __init__(self, memory: DualIncidentMemory) -> None:
+        self._memory = memory
+        self._lua_create_sha: str | None = None
+        self._lua_aggregate_sha: str | None = None
+
+    async def _ensure_lua_scripts(self) -> None:
+        """確保 Lua Scripts 已載入"""
+        if self._lua_create_sha:
+            return
+        redis_client = get_redis()
+        self._lua_create_sha = await redis_client.script_load(LUA_CREATE_OR_AGGREGATE)
+        self._lua_aggregate_sha = await redis_client.script_load(LUA_AGGREGATE_SIGNAL)
+
+    async def load_incident(self, incident_id: str) -> Incident | None:
+        """從 Working Memory 載入 Incident"""
+        return await self._memory.load_incident(incident_id)
+
+    async def save_incident(
+        self, incident: Incident, ttl_seconds: int = 604800
+    ) -> bool:
+        """儲存 Incident 到 Working Memory"""
+        try:
+            redis_client = get_redis()
+            key = f"{INCIDENT_KEY_PREFIX}{incident.incident_id}"
+            await redis_client.set(key, incident.model_dump_json(), ex=ttl_seconds)
+            return True
+        except Exception as e:
+            logger.exception("save_incident_error", error=str(e))
+            return False
+
+    async def persist_incident(self, incident: Incident) -> bool:
+        """持久化到 Episodic Memory (PostgreSQL)"""
+        return await self._memory.persist_incident(incident)
+
+    async def find_related_incident(
+        self,
+        namespace: str,
+        target: str,
+        window_minutes: int = 30,  # noqa: ARG002
+    ) -> Incident | None:
+        """尋找相關的活躍 Incident (用於聚合)"""
+        redis_client = get_redis()
+
+        # 嘗試 namespace 索引
+        ns_key = f"{INCIDENT_INDEX_NS}{namespace}"
+        incident_id = await redis_client.get(ns_key)
+
+        if not incident_id:
+            # 嘗試 target 索引
+            target_key = f"{INCIDENT_INDEX_TARGET}{target}"
+            incident_id = await redis_client.get(target_key)
+
+        if incident_id:
+            if isinstance(incident_id, bytes):
+                incident_id = incident_id.decode()
+            return await self.load_incident(incident_id)
+
+        return None
+
+    async def update_index(
+        self,
+        incident_id: str,
+        namespace: str,
+        target: str,
+    ) -> bool:
+        """更新反向索引"""
+        try:
+            redis_client = get_redis()
+            ttl = AGGREGATION_WINDOW_SECONDS
+
+            ns_key = f"{INCIDENT_INDEX_NS}{namespace}"
+            target_key = f"{INCIDENT_INDEX_TARGET}{target}"
+
+            await redis_client.set(ns_key, incident_id, ex=ttl, nx=True)
+            await redis_client.set(target_key, incident_id, ex=ttl, nx=True)
+            return True
+        except Exception as e:
+            logger.exception("update_index_error", error=str(e))
+            return False
+
+
+class BlastRadiusAdapter:
+    """
+    Blast Radius Adapter - 實作 lewooogo-brain 的 IBlastRadiusAnalyzer Protocol
+
+    Phase 16 R1.3: 包裝現有 topology_graph
+
+    版本: v1.0
+    建立: 2026-03-26 (台北時區)
+    建立者: Claude Code
+    """
+
+    def __init__(self, graph=None) -> None:
+        self._graph = graph or topology_graph
+
+    def analyze(self, target: str) -> list[str]:
+        """分析受影響的服務列表"""
+        try:
+            result: BlastRadiusResult = self._graph.get_blast_radius(target)
+            return result.affected_services
+        except Exception as e:
+            logger.warning("blast_radius_analysis_failed", target=target, error=str(e))
+            return [target] if target != "unknown" else []
+
+
+# =============================================================================
+# Singleton + 絞殺者模式切換
 # =============================================================================
 
 _incident_engine: IncidentEngine | None = None
+_new_incident_engine = None  # Type: lewooogo_brain IncidentEngine
 
 
-def get_incident_engine() -> IncidentEngine:
-    """取得 Incident Engine 實例 (Singleton)"""
+def _get_new_engine():
+    """取得 lewooogo-brain 的 IncidentEngine (Phase 16 新版)"""
+    global _new_incident_engine
+    if _new_incident_engine is None:
+        from lewooogo_brain.engines import IncidentEngine as NewIncidentEngine
+
+        # 建立 Adapters
+        memory_adapter = IncidentMemoryAdapter(get_incident_memory())
+        blast_adapter = BlastRadiusAdapter()
+
+        _new_incident_engine = NewIncidentEngine(
+            memory=memory_adapter,
+            blast_analyzer=blast_adapter,
+            logger=logger,
+        )
+        logger.info("new_incident_engine_initialized", version="lewooogo-brain")
+    return _new_incident_engine
+
+
+def _get_legacy_engine() -> IncidentEngine:
+    """取得舊版 IncidentEngine"""
     global _incident_engine
     if _incident_engine is None:
         _incident_engine = IncidentEngine()
     return _incident_engine
+
+
+def get_incident_engine():
+    """
+    取得 Incident Engine 實例 (Singleton + 絞殺者模式)
+
+    Phase 16: 根據 USE_NEW_ENGINE 設定切換引擎
+    - False (預設): 使用內嵌版 IncidentEngine
+    - True: 使用 lewooogo-brain 的 IncidentEngine
+
+    回滾方式:
+        kubectl set env deployment/awoooi-api USE_NEW_ENGINE=false
+    """
+    from src.core.config import settings
+
+    if settings.USE_NEW_ENGINE:
+        logger.debug("using_new_incident_engine", version="lewooogo-brain")
+        return _get_new_engine()
+    else:
+        return _get_legacy_engine()