feat: 高德IoT v5 API升级、电子围栏管理、设备绑定自动考勤

- 前向地理编码升级为高德IoT v5 API (POST restapi.amap.com/v5/position/IoT)
- 修复LBS定位偏差: 添加network=LTE参数区分4G/2G, bts格式补充cage字段
- 新增电子围栏管理模块 (circle/polygon/rectangle), 支持地图绘制和POI搜索
- 新增设备-围栏多对多绑定 (DeviceFenceBinding/DeviceFenceState)
- 围栏自动考勤引擎 (fence_checker.py): haversine距离、ray-casting多边形判定、容差机制、防抖
- TCP位置上报自动检测围栏进出, 生成考勤记录并WebSocket广播
- 前端围栏页面: 绑定设备弹窗、POI搜索定位、左侧围栏面板
- 新增fence_attendance WebSocket topic

via [HAPI](https://hapi.run)

Co-Authored-By: HAPI <noreply@hapi.run>

app/config.py

@@ -1,9 +1,17 @@
+from datetime import datetime, timedelta, timezone
 from pathlib import Path
 from typing import Literal
 
 from pydantic import Field
 from pydantic_settings import BaseSettings
 
+CST = timezone(timedelta(hours=8))
+
+
+def now_cst() -> datetime:
+    """Return current time in CST (UTC+8) as naive datetime for SQLite."""
+    return datetime.now(CST).replace(tzinfo=None)
+
 # Project root directory (where config.py lives → parent = app/ → parent = project root)
 _PROJECT_ROOT = Path(__file__).resolve().parent.parent
 _DEFAULT_DB_PATH = _PROJECT_ROOT / "badge_admin.db"
@@ -30,8 +38,10 @@ class Settings(BaseSettings):
     RATE_LIMIT_WRITE: str = Field(default="30/minute", description="Rate limit for write operations")
 
     # 高德地图 API (geocoding)
-    AMAP_KEY: str | None = Field(default=None, description="高德地图 Web API key")
-    AMAP_SECRET: str | None = Field(default=None, description="高德地图安全密钥")
+    AMAP_KEY: str | None = Field(default=None, description="高德地图 Web服务 key (逆地理编码/POI搜索)")
+    AMAP_SECRET: str | None = Field(default=None, description="高德地图 Web服务安全密钥")
+    AMAP_HARDWARE_KEY: str | None = Field(default=None, description="高德地图智能硬件定位 key (基站/WiFi定位)")
+    AMAP_HARDWARE_SECRET: str | None = Field(default=None, description="高德地图智能硬件定位安全密钥 (与 HARDWARE_KEY 配对)")
 
     # Geocoding
     GEOCODING_DEFAULT_IMEI: str = Field(default="868120334031363", description="Default IMEI for AMAP geocoding API")
@@ -40,6 +50,12 @@ class Settings(BaseSettings):
     # Track query limit
     TRACK_MAX_POINTS: int = Field(default=10000, description="Maximum points returned by track endpoint")
 
+    # Fence auto-attendance
+    FENCE_CHECK_ENABLED: bool = Field(default=True, description="Enable automatic fence attendance check on location report")
+    FENCE_LBS_TOLERANCE_METERS: int = Field(default=200, description="Extra tolerance (meters) for LBS locations in fence check")
+    FENCE_WIFI_TOLERANCE_METERS: int = Field(default=100, description="Extra tolerance (meters) for WiFi locations in fence check")
+    FENCE_MIN_INSIDE_SECONDS: int = Field(default=60, description="Minimum seconds between fence attendance transitions (debounce)")
+
     # Data retention
     DATA_RETENTION_DAYS: int = Field(default=90, description="Days to keep location/heartbeat/alarm/attendance/bluetooth records")
     DATA_CLEANUP_INTERVAL_HOURS: int = Field(default=24, description="Hours between automatic cleanup runs")