fix: 剩余服务文件时间统一为北京时间

- agent_dispatcher、alert_service、report_generator、
  oss_storage、work_order_service 全部使用 beijing_now()
- 全局无遗留 UTC 时间调用

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

app/services/agent_dispatcher.py

@@ -11,13 +11,14 @@
 """
 
 import json
-from datetime import datetime, timedelta, timezone
+from datetime import timedelta
 from typing import Dict, Optional
 
 from openai import AsyncOpenAI
 
 from app.config import settings
 from app.utils.logger import logger
+from app.utils.timezone import beijing_now
 
 INTENT_SYSTEM_PROMPT = """你是物业安防AI助手。根据用户消息识别意图，仅输出JSON。
 
@@ -144,7 +145,7 @@ class AgentDispatcher:
 
         # 解析时间范围
         time_range = params.get("time_range", "today")
-        now = datetime.now(timezone.utc)
+        now = beijing_now()
         if time_range == "week":
             start = now - timedelta(days=now.weekday())
             start = start.replace(hour=0, minute=0, second=0, microsecond=0)

app/services/alert_service.py

@@ -3,13 +3,14 @@
 处理告警 CRUD（旧版告警系统，已迁移至 alarm_event_service）
 """
 import uuid
-from datetime import datetime, timezone
+from datetime import datetime
 from typing import Optional, List, Dict, Any
 
 from app.models import Alert, AlertStatus, AlertLevel, get_session
 from app.schemas import AlertCreate, AlertHandleRequest
 from app.services.oss_storage import get_oss_storage
 from app.utils.logger import logger
+from app.utils.timezone import beijing_now
 
 
 class AlertService:
@@ -20,7 +21,7 @@ class AlertService:
 
     def generate_alert_no(self) -> str:
         """生成告警编号"""
-        timestamp = datetime.now(timezone.utc).strftime("%Y%m%d%H%M%S")
+        timestamp = beijing_now().strftime("%Y%m%d%H%M%S")
         unique_id = uuid.uuid4().hex[:8].upper()
         return f"ALT{timestamp}{unique_id}"
 
@@ -161,8 +162,8 @@ class AlertService:
             alert.status = AlertStatus(handle_data.status)
             alert.handle_remark = handle_data.remark
             alert.handled_by = handled_by
-            alert.handled_at = datetime.now(timezone.utc)
-            alert.updated_at = datetime.now(timezone.utc)
+            alert.handled_at = beijing_now()
+            alert.updated_at = beijing_now()
 
             db.commit()
             db.refresh(alert)
@@ -183,7 +184,7 @@ class AlertService:
 
             alert.status = AlertStatus.DISPATCHED
             alert.work_order_id = work_order_id
-            alert.updated_at = datetime.now(timezone.utc)
+            alert.updated_at = beijing_now()
 
             db.commit()
             db.refresh(alert)

app/services/oss_storage.py

@@ -8,12 +8,13 @@
 import os
 import time
 import uuid
-from datetime import datetime, timezone
+from datetime import datetime
 from typing import Optional
 from pathlib import Path
 
 from app.config import settings
 from app.utils.logger import logger
+from app.utils.timezone import beijing_now
 
 
 # 按需导入 COS SDK
@@ -148,7 +149,7 @@ def _generate_object_key(prefix: str = "", ext: str = ".jpg") -> str:
     生成对象存储 Key
     格式: {prefix}/{YYYY}/{MM}/{DD}/{YYYYMMDDHHmmss}_{uuid8}{ext}
     """
-    now = datetime.now(timezone.utc)
+    now = beijing_now()
     date_path = now.strftime("%Y/%m/%d")
     timestamp = now.strftime("%Y%m%d%H%M%S")
     unique_id = uuid.uuid4().hex[:8].upper()

app/services/report_generator.py

@@ -5,7 +5,7 @@
 """
 
 import io
-from datetime import datetime, timedelta, timezone
+from datetime import timedelta
 from typing import Optional, Tuple
 
 from openpyxl import Workbook
@@ -13,6 +13,7 @@ from openpyxl.styles import Font, PatternFill, Alignment, Border, Side
 
 from app.models import AlarmEvent, get_session
 from app.utils.logger import logger
+from app.utils.timezone import beijing_now
 
 
 TYPE_NAMES = {"leave_post": "人员离岗", "intrusion": "周界入侵"}
@@ -35,7 +36,7 @@ def generate_alarm_report(
     Returns:
         (filename, bytes_io) 或 None（无数据时）
     """
-    now = datetime.now(timezone.utc)
+    now = beijing_now()
     if time_range == "today":
         start = now.replace(hour=0, minute=0, second=0, microsecond=0)
         label = now.strftime("%Y%m%d")

app/services/work_order_service.py

@@ -6,16 +6,16 @@
 """
 
 import uuid
-from datetime import datetime, timezone
 from typing import Optional, Dict, List, Tuple
 
 from app.models import WorkOrder, WorkOrderStatus, WorkOrderPriority, get_session
 from app.utils.logger import logger
+from app.utils.timezone import beijing_now
 
 
 def generate_order_no() -> str:
     """生成工单编号: WO + YYYYMMDDHHmmss + 6位uuid"""
-    ts = datetime.now(timezone.utc).strftime("%Y%m%d%H%M%S")
+    ts = beijing_now().strftime("%Y%m%d%H%M%S")
     return f"WO{ts}{uuid.uuid4().hex[:6].upper()}"
 
 
@@ -114,7 +114,7 @@ class WorkOrderService:
             if result:
                 order.result = result
 
-            now = datetime.now(timezone.utc)
+            now = beijing_now()
             if status == "processing" and not order.started_at:
                 order.started_at = now
             elif status == "completed":