feat: 性能优化 + 设备总览轨迹展示 + 广播指令API

性能: SQLite WAL模式、aiohttp Session复用、TCP连接锁+空闲超时、
device_id缓存、WebSocket并发广播、API Key认证缓存、围栏N+1查询
批量化、逆地理编码并行化、新增5个DB索引、日志降级DEBUG

功能: 广播指令API(broadcast)、exclude_type低精度后端过滤、
前端设备总览Tab+多设备轨迹叠加+高亮联动+搜索+专属颜色

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

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

app/database.py

@@ -1,3 +1,4 @@
+from sqlalchemy import event
 from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
 from sqlalchemy.orm import DeclarativeBase
 
@@ -9,6 +10,17 @@ engine = create_async_engine(
     connect_args={"check_same_thread": False},
 )
 
+# Enable WAL mode for concurrent read/write performance
+@event.listens_for(engine.sync_engine, "connect")
+def _set_sqlite_pragma(dbapi_conn, connection_record):
+    cursor = dbapi_conn.cursor()
+    cursor.execute("PRAGMA journal_mode=WAL")
+    cursor.execute("PRAGMA synchronous=NORMAL")
+    cursor.execute("PRAGMA cache_size=-64000")  # 64MB cache
+    cursor.execute("PRAGMA busy_timeout=5000")  # 5s wait on lock
+    cursor.execute("PRAGMA foreign_keys=ON")
+    cursor.close()
+
 async_session = async_sessionmaker(
     bind=engine,
     class_=AsyncSession,