fix(api): resolve 時 DB 記錄不存在視為成功

根因: Incident 可能因 DB 寫入失敗只存在於 Redis
修復: 只要 Redis 更新成功就算成功 (API 只讀 Redis)

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

apps/api/src/services/proposal_service.py

@@ -569,7 +569,7 @@ class ProposalService:
                 error=str(e),
             )
 
-        # 2. 更新 DB
+        # 2. 更新 DB (如果存在)
         try:
             async with get_db_context() as db:
                 stmt = select(IncidentRecord).where(
@@ -586,6 +586,15 @@ class ProposalService:
                         "resolve_incident_db_updated",
                         incident_id=incident_id,
                     )
+                else:
+                    # DB 沒有記錄但 Redis 有 - 這是可接受的狀態
+                    # (Incident 可能因 DB 寫入失敗只存在 Redis)
+                    db_ok = True  # 視為成功，因為沒有需要更新的記錄
+                    logger.warning(
+                        "resolve_incident_db_not_found",
+                        incident_id=incident_id,
+                        note="Incident exists in Redis but not in DB, this is acceptable",
+                    )
         except Exception as e:
             logger.exception(
                 "resolve_incident_db_error",
@@ -593,7 +602,8 @@ class ProposalService:
                 error=str(e),
             )
 
-        success = redis_ok and db_ok
+        # 只要 Redis 更新成功就算成功（API 只讀 Redis）
+        success = redis_ok
         logger.info(
             "resolve_incident_completed",
             incident_id=incident_id,