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/routers/commands.py

@@ -317,6 +317,81 @@ async def batch_send_command(request: Request, body: BatchCommandRequest, db: As
     )
 
 
+class BroadcastCommandRequest(BaseModel):
+    """Request body for broadcasting a command to all devices."""
+    command_type: str = Field(default="online_cmd", max_length=30, description="指令类型")
+    command_content: str = Field(..., max_length=500, description="指令内容")
+
+
+@router.post(
+    "/broadcast",
+    response_model=APIResponse[BatchCommandResponse],
+    status_code=201,
+    summary="广播指令给所有设备 / Broadcast command to all devices",
+    dependencies=[Depends(require_write)],
+)
+@limiter.limit(settings.RATE_LIMIT_WRITE)
+async def broadcast_command(request: Request, body: BroadcastCommandRequest, db: AsyncSession = Depends(get_db)):
+    """
+    向所有设备广播同一指令。尝试通过 TCP 发送给每台设备，TCP 未连接的自动跳过。
+    Broadcast the same command to all devices. Attempts TCP send for each, skips those without active TCP connection.
+    """
+    from sqlalchemy import select
+    from app.models import Device
+
+    result = await db.execute(select(Device))
+    devices = list(result.scalars().all())
+
+    if not devices:
+        return APIResponse(
+            message="No devices / 没有设备",
+            data=BatchCommandResponse(total=0, sent=0, failed=0, results=[]),
+        )
+
+    results = []
+    for device in devices:
+        if not tcp_command_service.is_device_online(device.imei):
+            results.append(BatchCommandResult(
+                device_id=device.id, imei=device.imei,
+                success=False, error="TCP not connected",
+            ))
+            continue
+
+        try:
+            cmd_log = await command_service.create_command(
+                db,
+                device_id=device.id,
+                command_type=body.command_type,
+                command_content=body.command_content,
+            )
+            await tcp_command_service.send_command(
+                device.imei, body.command_type, body.command_content
+            )
+            cmd_log.status = "sent"
+            cmd_log.sent_at = now_cst()
+            await db.flush()
+            await db.refresh(cmd_log)
+            results.append(BatchCommandResult(
+                device_id=device.id, imei=device.imei,
+                success=True, command_id=cmd_log.id,
+            ))
+        except Exception as e:
+            logging.getLogger(__name__).error("Broadcast cmd failed for %s: %s", device.imei, e)
+            results.append(BatchCommandResult(
+                device_id=device.id, imei=device.imei,
+                success=False, error="Send failed",
+            ))
+
+    sent = sum(1 for r in results if r.success)
+    failed = len(results) - sent
+    return APIResponse(
+        message=f"Broadcast: {sent} sent, {failed} skipped (total: {len(devices)})",
+        data=BatchCommandResponse(
+            total=len(results), sent=sent, failed=failed, results=results,
+        ),
+    )
+
+
 @router.get(
     "/{command_id}",
     response_model=APIResponse[CommandResponse],