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/websocket_manager.py

@@ -62,17 +62,22 @@ class WebSocketManager:
             ensure_ascii=False,
         )
 
-        disconnected = []
-        # Snapshot dict to avoid RuntimeError from concurrent modification
-        for ws, topics in list(self.active_connections.items()):
-            if topic in topics:
-                try:
-                    await ws.send_text(message)
-                except Exception:
-                    disconnected.append(ws)
+        # Send to all subscribers concurrently with timeout
+        subscribers = [(ws, topics) for ws, topics in list(self.active_connections.items()) if topic in topics]
+        if not subscribers:
+            return
 
-        for ws in disconnected:
-            self.active_connections.pop(ws, None)
+        async def _safe_send(ws):
+            try:
+                await asyncio.wait_for(ws.send_text(message), timeout=3.0)
+                return None
+            except Exception:
+                return ws
+
+        results = await asyncio.gather(*[_safe_send(ws) for ws, _ in subscribers])
+        for ws in results:
+            if ws is not None:
+                self.active_connections.pop(ws, None)
 
     def broadcast_nonblocking(self, topic: str, data: dict):
         """Fire-and-forget broadcast (used from TCP handler context)."""