refactor(api): Phase 17 P1 Tier 3 紅區服務 Protocol 定義

新增 5 個紅區核心服務的 Protocol 介面：
- IDecisionManager: 決策狀態機
- ITrustScoreManager: 信任評分引擎
- IIncidentEngine: 事件處理引擎
- IMultiSigRedisService: 分散式鎖服務
- ITelegramSecurityInterceptor: 安全攔截器

符合 leWOOOgo 積木化規範：
- 支援依賴注入 (DI)
- 便於測試時 Mock
- 型別約束確保實作一致性

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

apps/api/src/services/incident_engine.py

@@ -30,7 +30,7 @@ v1.1 重構內容 (2026-03-22 架構師審查後修正):
 
 import json
 from datetime import UTC, datetime
-from typing import Any
+from typing import Any, Protocol, runtime_checkable
 
 import structlog
 
@@ -234,6 +234,46 @@ return "AGGREGATED:" .. updated_json
 """
 
 
+# =============================================================================
+# Protocol Interface (Phase 17 P1 - 紅區治理)
+# =============================================================================
+
+@runtime_checkable
+class IIncidentEngine(Protocol):
+    """
+    IncidentEngine 介面定義
+
+    用途:
+    - 依賴注入 (DI) 時的型別約束
+    - 測試時 Mock 的型別檢查
+    - 符合 leWOOOgo 積木化規範
+
+    Tier 3 紅區服務: 修改需首席架構師簽核
+
+    @see feedback_lewooogo_modular_enforcement.md
+    @see docs/RED_ZONES.md
+    """
+
+    async def process_signal(
+        self,
+        signal_data: dict[str, Any],
+    ) -> Incident | None:
+        """處理 Signal: 原子建立或聚合 Incident"""
+        ...
+
+    async def get_incident(self, incident_id: str) -> Incident | None:
+        """取得指定 Incident"""
+        ...
+
+    async def update_incident_status(
+        self,
+        incident_id: str,
+        status: str,
+    ) -> Incident | None:
+        """更新 Incident 狀態"""
+        ...
+
+
 # =============================================================================
 # Incident Engine v1.1
 # =============================================================================