fix(service): #123 proposal_service.py 修正 key prefix + 移除重複邏輯

ADR-046 修復: proposal_service 使用錯誤 Redis key prefix "incident:"
(brain 使用 "awoooi:incidents:")，導致 R-R2 後 load/persist 失效。

變更:
- _load_incident(): 委派給 IncidentEngineAdapter.get_incident()
  (正確 key prefix，含 brain→local 型別轉換)
- _persist_incident(): Redis 部分委派給 brain DualIncidentMemory
  透過 local_to_brain() 轉換後儲存 (key prefix 一致)
- 移除 _record_to_incident() 重複邏輯 (已由 IncidentEngineAdapter 處理)
- 移除 INCIDENT_KEY_PREFIX 常數
- 移除 get_redis() 直接依賴

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

apps/api/src/services/proposal_service.py

@@ -19,11 +19,9 @@ Decision Proposal Service - Phase 6.4 決策輸出層
 """
 
 from datetime import UTC, datetime
-from uuid import UUID
 
 import structlog
 
-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.approval import (
@@ -42,8 +40,11 @@ from src.models.incident import (
     Severity,
 )
 from src.services.approval_db import get_approval_service
+from src.services.incident_engine import get_incident_engine
+from src.services.incident_memory import get_incident_memory
 from src.services.openclaw import get_openclaw
 from src.services.trust_engine import normalize_action_pattern, trust_engine
+from src.utils.incident_converter import local_to_brain
 
 logger = structlog.get_logger(__name__)
 
@@ -52,8 +53,6 @@ logger = structlog.get_logger(__name__)
 # Constants
 # =============================================================================
 
-INCIDENT_KEY_PREFIX = "incident:"
-
 # Severity → RiskLevel 對應
 SEVERITY_TO_RISK = {
     Severity.P0: ApprovalRiskLevel.CRITICAL,  # P0 (critical) → CRITICAL (2 簽核)
@@ -292,67 +291,21 @@ class ProposalService:
 
     async def _load_incident(self, incident_id: str) -> Incident | None:
         """
-        載入 Incident (Redis 優先，DB 備援)
+        載入 Incident (委派給 IncidentEngineAdapter)
+
+        ADR-046 (2026-04-01 ogt): 透過 IncidentEngineAdapter.get_incident()
+        取得 LocalIncident，key prefix 正確性由 brain DualIncidentMemory 保證
+        (awoooi:incidents:{id})，不再直接存取 Redis。
         """
-        redis_client = get_redis()
-        key = f"{INCIDENT_KEY_PREFIX}{incident_id}"
-
-        # 1. 嘗試從 Redis 載入
         try:
-            data = await redis_client.get(key)
-            if data:
-                return Incident.model_validate_json(data)
+            return await get_incident_engine().get_incident(incident_id)
         except Exception as e:
             logger.warning(
-                "redis_load_failed",
+                "load_incident_failed",
                 incident_id=incident_id,
                 error=str(e),
             )
-
-        # 2. 從 DB 載入
-        try:
-            async with get_db_context() as db:
-                from sqlalchemy import select
-
-                stmt = select(IncidentRecord).where(
-                    IncidentRecord.incident_id == incident_id
-                )
-                result = await db.execute(stmt)
-                record = result.scalar_one_or_none()
-
-                if record:
-                    return self._record_to_incident(record)
-        except Exception as e:
-            logger.warning(
-                "db_load_failed",
-                incident_id=incident_id,
-                error=str(e),
-            )
-
-        return None
-
-    def _record_to_incident(self, record: IncidentRecord) -> Incident:
-        """將 DB Record 轉換為 Incident"""
-        from src.models.incident import Signal
-
-        signals = [
-            Signal.model_validate(s) for s in (record.signals or [])
-        ]
-
-        return Incident(
-            incident_id=record.incident_id,
-            status=IncidentStatus(record.status.lower()),
-            severity=Severity(record.severity),
-            signals=signals,
-            affected_services=record.affected_services or [],
-            proposal_ids=[UUID(pid) for pid in (record.proposal_ids or [])],
-            decision_chain=None,  # DB 不存完整決策鏈
-            outcome=None,  # DB 存結果狀態而非完整 outcome
-            created_at=record.created_at,
-            updated_at=record.updated_at,
-            resolved_at=record.resolved_at,
-            closed_at=record.closed_at,
-        )
+            return None
 
     # =========================================================================
     # 輔助方法: 決定修復動作
@@ -466,17 +419,15 @@ class ProposalService:
     async def _persist_incident(self, incident: Incident) -> None:
         """
         更新 Incident 到 Redis + DB
-        """
-        redis_client = get_redis()
-        key = f"{INCIDENT_KEY_PREFIX}{incident.incident_id}"
 
-        # 1. 更新 Redis
+        ADR-046 (2026-04-01 ogt): Redis 委派給 brain DualIncidentMemory
+        確保 key prefix 一致性 (awoooi:incidents:{id})。
+        DB 直接更新 status + proposal_ids (最小化變更)。
+        """
+        # 1. 更新 Redis (委派給 brain DualIncidentMemory)
         try:
-            await redis_client.set(
-                key,
-                incident.model_dump_json(),
-                ex=604800,  # 7 days
-            )
+            brain_incident = local_to_brain(incident)
+            await get_incident_memory().save_incident(brain_incident)
         except Exception as e:
             logger.warning(
                 "redis_persist_failed",