feat(types): ADR-046 IncidentConverter + IncidentEngineAdapter

實作 ADR-046 Option B: IncidentConverter 轉換層，解決
BrainIncident (lewooogo-brain) 與 LocalIncident (apps/api) 型別邊界問題。

變更:
- 新增 src/utils/incident_converter.py
  - brain_to_local(): BrainIncident → LocalIncident
  - local_to_brain(): LocalIncident → BrainIncident
  - ESCALATED → MITIGATING 映射 (brain 無 ESCALATED)
- incident_engine.py: 新增 IncidentEngineAdapter 包裝層
  - process_signal() / get_incident() 輸出轉換為 LocalIncident
  - get_incident_engine() 返回 IncidentEngineAdapter
- incident_memory.py: 加入 brain_to_local import，更新 _record_to_incident 說明
- ADR-046: 標記三個轉換點全部完成

解鎖: #123 proposal_service.py 清理 (下一步)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/api/src/services/incident_engine.py

@@ -28,6 +28,7 @@ from src.core.redis_client import get_redis
 from src.models.incident import Incident
 from src.services.graph_rag import BlastRadiusResult, topology_graph
 from src.services.incident_memory import get_incident_memory
+from src.utils.incident_converter import brain_to_local
 
 logger = structlog.get_logger(__name__)
 
@@ -69,11 +70,11 @@ class IIncidentEngine(Protocol):
         self,
         signal_data: dict[str, Any],
     ) -> Incident | None:
-        """處理 Signal: 原子建立或聚合 Incident"""
+        """處理 Signal: 原子建立或聚合 Incident (返回 LocalIncident，ADR-046)"""
         ...
 
     async def get_incident(self, incident_id: str) -> Incident | None:
-        """取得指定 Incident"""
+        """取得指定 Incident (返回 LocalIncident，ADR-046)"""
         ...
 
     async def update_status(
@@ -106,7 +107,13 @@ class IncidentMemoryAdapter:
         self._memory = memory
 
     async def load_incident(self, incident_id: str) -> Any:
-        """從 Working Memory 載入 Incident"""
+        """
+        從 Working Memory 載入 Incident (返回 BrainIncident，供 brain engine 內部使用)
+
+        注意: 此 adapter 注入 brain engine，brain 內部呼叫時期望 BrainIncident。
+        本地服務透過 IncidentEngineAdapter.get_incident() 取得 LocalIncident。
+        (ADR-046 - 2026-04-01 ogt)
+        """
         return await self._memory.load_incident(incident_id)
 
     async def save_incident(self, incident: Any, ttl_seconds: int = 604800) -> bool:
@@ -188,18 +195,56 @@ class BlastRadiusAdapter:
             return [target] if target != "unknown" else []
 
 
+# =============================================================================
+# IncidentEngineAdapter (ADR-046: brain 輸出轉換為 LocalIncident)
+# =============================================================================
+
+class IncidentEngineAdapter:
+    """
+    Incident Engine Adapter - 包裝 lewooogo-brain IncidentEngine
+
+    ADR-046 (2026-04-01 ogt): brain 引擎輸出 BrainIncident，
+    透過 brain_to_local() 轉換為 LocalIncident，供本地服務消費。
+
+    這是本地服務與 brain 引擎之間的邊界層。
+    讓 IIncidentEngine Protocol 的返回型別宣告 Incident 得以成立。
+    """
+
+    def __init__(self, brain_engine: Any) -> None:
+        self._engine = brain_engine
+
+    async def process_signal(self, signal_data: dict[str, Any]) -> Incident | None:
+        """處理 Signal，返回 LocalIncident (brain 輸出轉換)"""
+        brain_incident = await self._engine.process_signal(signal_data)
+        if brain_incident is None:
+            return None
+        return brain_to_local(brain_incident)
+
+    async def get_incident(self, incident_id: str) -> Incident | None:
+        """取得 Incident，返回 LocalIncident (brain 輸出轉換)"""
+        brain_incident = await self._engine.get_incident(incident_id)
+        if brain_incident is None:
+            return None
+        return brain_to_local(brain_incident)
+
+    async def update_status(self, incident_id: str, status: Any) -> bool:
+        """更新狀態 (直接委派，brain status 與 local status 值相容)"""
+        return await self._engine.update_status(incident_id, status)
+
+
 # =============================================================================
 # Singleton (Phase R-R2: 僅保留 lewooogo-brain 版本)
 # =============================================================================
 
-_new_incident_engine: Any | None = None
+_new_incident_engine: IncidentEngineAdapter | None = None
 
 
-def get_incident_engine() -> Any:
+def get_incident_engine() -> IncidentEngineAdapter:
     """
     取得 Incident Engine 實例 (Singleton)
 
     Phase R-R2: 統一使用 lewooogo-brain IncidentEngine。
+    ADR-046: 返回 IncidentEngineAdapter，輸出已轉換為 LocalIncident。
     回滾方式: git revert Phase R-R2 commit + redeploy。
 
     Raises:
@@ -214,12 +259,13 @@ def get_incident_engine() -> Any:
             memory_adapter = IncidentMemoryAdapter(get_incident_memory())
             blast_adapter = BlastRadiusAdapter()
 
-            _new_incident_engine = NewIncidentEngine(
+            brain_engine = NewIncidentEngine(
                 memory=memory_adapter,
                 blast_analyzer=blast_adapter,
                 logger=logger,
             )
-            logger.info("incident_engine_initialized", version="lewooogo-brain")
+            _new_incident_engine = IncidentEngineAdapter(brain_engine)
+            logger.info("incident_engine_initialized", version="lewooogo-brain", adapter="IncidentEngineAdapter")
 
         except ImportError as e:
             logger.error("lewooogo_brain_engines_not_available", error=str(e))

apps/api/src/services/incident_memory.py

@@ -25,6 +25,7 @@ from src.core.redis_client import get_redis
 from src.db.base import get_db_context
 from src.db.models import IncidentRecord
 from src.models.incident import Incident
+from src.utils.incident_converter import brain_to_local
 
 logger = structlog.get_logger(__name__)
 
@@ -121,9 +122,13 @@ class IncidentDbAdapter:
             return False
 
     def _record_to_incident(self, record: IncidentRecord) -> Any:
-        # 2026-04-01 ogt: 返回 BrainIncident (lewooogo-brain)，非本地 Incident
-        # 型別為 Any 避免靜態分析誤報，實際為 lewooogo_brain.interfaces.incident_processor.Incident
-        """將 DB Record 轉換為 Incident (lewooogo-brain 版本)"""
+        """
+        將 DB Record 轉換為 BrainIncident (lewooogo-brain 版本)
+
+        注意: 返回 BrainIncident 供 lewooogo-brain DualIncidentMemory 內部使用。
+        本地服務消費時透過 IncidentConverter.brain_to_local() 轉換。
+        (ADR-046 - 2026-04-01 ogt)
+        """
         from lewooogo_brain.interfaces.incident_processor import (
             Incident as BrainIncident,
         )