feat(api): Phase 16 R1.2 絞殺者模式 (Strangler Fig Pattern)

- 新增 USE_NEW_ENGINE 設定開關 (預設 False)
- incident_memory.py 雙軌切換: 內嵌版本 ↔ lewooogo-brain
- 自動降級: lewooogo-brain 不可用時回退內嵌版本
- 回滾指令: kubectl set env deployment/awoooi-api USE_NEW_ENGINE=false

統帥批准 2026-03-26 立即執行

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

apps/api/src/core/config.py

@@ -51,6 +51,21 @@ class Settings(BaseSettings):
         description="Enable mock mode for external services (Redis, Ollama, OpenClaw, PostgreSQL, SigNoz)",
     )
 
+    # ==========================================================================
+    # Phase 16: leWOOOgo 積木化絞殺者模式 (Strangler Fig Pattern)
+    # 2026-03-26 統帥批准立即執行
+    #
+    # 功能開關:
+    # - False: 使用 apps/api 內嵌版本 (當前)
+    # - True: 使用 lewooogo-brain/lewooogo-data 套件版本
+    #
+    # 回滾指令: kubectl set env deployment/awoooi-api USE_NEW_ENGINE=false
+    # ==========================================================================
+    USE_NEW_ENGINE: bool = Field(
+        default=False,
+        description="Phase 16: True=lewooogo packages, False=內嵌版本",
+    )
+
     # ==========================================================================
     # CORS - 嚴格白名單 (無 UAT, 無 wildcard)
     # ==========================================================================

apps/api/src/services/incident_memory.py

@@ -2,6 +2,7 @@
 Incident Memory Provider - 事件記憶體提供者
 ============================================
 Phase 6.4e: DualIncidentMemory 整合
+Phase 16 R1.2: 絞殺者模式 (Strangler Fig Pattern) 2026-03-26
 
 設計:
 - 實作 IIncidentMemory 協定 (Protocol)
@@ -13,8 +14,14 @@ Phase 6.4e: DualIncidentMemory 整合
 - Episodic Memory (PostgreSQL): 永久
 - 反向索引: 30 分鐘 TTL (聚合窗口)
 
+Phase 16 絞殺者模式:
+- USE_NEW_ENGINE=False: 使用此內嵌版本 (當前預設)
+- USE_NEW_ENGINE=True:  使用 lewooogo-brain 套件版本
+- 回滾指令: kubectl set env deployment/awoooi-api USE_NEW_ENGINE=false
+- 監控週期: 48 小時驗證期
+
 NOTE: 此模組為 lewooogo-brain/adapters/incident_memory.py 的 apps/api 內嵌版本
-      待 Phase 6.4i 完成 monorepo Docker 解法後，將直接引用 lewooogo-brain 套件
+      Phase 16 R2 階段會在 48 小時驗證通過後移除此檔案
 """
 
 from datetime import UTC, datetime, timedelta
@@ -469,15 +476,91 @@ class DualIncidentMemory:
 
 
 # =============================================================================
-# Singleton
+# Singleton + 絞殺者模式 (Phase 16 R1.2)
 # =============================================================================
 
 _dual_memory: DualIncidentMemory | None = None
+_new_engine_memory: Any | None = None  # lewooogo-brain 版本
 
 
 def get_incident_memory() -> DualIncidentMemory:
-    """取得 DualIncidentMemory 實例 (Singleton)"""
+    """
+    取得 DualIncidentMemory 實例 (Singleton)
+
+    Phase 16 絞殺者模式:
+    - USE_NEW_ENGINE=False (預設): 返回內嵌版本
+    - USE_NEW_ENGINE=True: 返回 lewooogo-brain 套件版本
+
+    回滾指令: kubectl set env deployment/awoooi-api USE_NEW_ENGINE=false
+    """
+    from src.core.config import settings
+
+    if settings.USE_NEW_ENGINE:
+        return _get_new_engine_memory()
+    else:
+        return _get_legacy_memory()
+
+
+def _get_legacy_memory() -> DualIncidentMemory:
+    """取得內嵌版本 (Phase 16 舊引擎)"""
     global _dual_memory
     if _dual_memory is None:
         _dual_memory = DualIncidentMemory()
+        logger.info("incident_memory_initialized", engine="legacy_embedded")
     return _dual_memory
+
+
+def _get_new_engine_memory() -> Any:
+    """
+    取得 lewooogo-brain 套件版本 (Phase 16 新引擎)
+
+    注意事項:
+    - 需要 lewooogo-brain 已安裝 (Dockerfile 已配置)
+    - PostgreSQL 整合尚未完成 (TODO in lewooogo-brain)
+    - 初次啟用建議 48 小時監控
+
+    回滾: 設定 USE_NEW_ENGINE=false 即可瞬間切回
+    """
+    global _new_engine_memory
+
+    if _new_engine_memory is None:
+        try:
+            # 延遲導入: 避免 lewooogo-brain 未安裝時啟動失敗
+            from lewooogo_brain.adapters.incident_memory import (
+                DualIncidentMemory as NewDualIncidentMemory,
+            )
+            from src.core.redis_client import get_redis
+            from src.db.base import get_db_context
+
+            redis_client = get_redis()
+
+            # 初始化 lewooogo-brain 版本
+            _new_engine_memory = NewDualIncidentMemory(
+                redis_client=redis_client,
+                pg_session_factory=get_db_context,
+                key_prefix="awoooi:incidents",
+            )
+
+            logger.info(
+                "incident_memory_initialized",
+                engine="lewooogo_brain_package",
+                redis_connected=True,
+            )
+
+        except ImportError as e:
+            # lewooogo-brain 未安裝，降級到內嵌版本
+            logger.warning(
+                "lewooogo_brain_not_available_fallback_to_legacy",
+                error=str(e),
+            )
+            return _get_legacy_memory()
+
+        except Exception as e:
+            # 其他錯誤，降級到內嵌版本
+            logger.error(
+                "new_engine_init_failed_fallback_to_legacy",
+                error=str(e),
+            )
+            return _get_legacy_memory()
+
+    return _new_engine_memory