feat: 告警/考勤/蓝牙/数据日志页面添加批量删除功能

- 新增 POST /api/alarms/batch-delete、/api/bluetooth/batch-delete、
  /api/heartbeats/batch-delete 批量删除端点 (最多500条)
- 四个页面表格添加全选复选框和"删除选中"按钮
- 提取通用 toggleAllCheckboxes/updateSelCount/_batchDelete 函数
- 数据日志页面根据当前查询类型自动路由到对应的批量删除API

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

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

app/routers/alarms.py

@@ -131,6 +131,32 @@ async def alarm_stats(db: AsyncSession = Depends(get_db)):
     )
 
 
+@router.post(
+    "/batch-delete",
+    response_model=APIResponse[dict],
+    summary="批量删除告警记录 / Batch delete alarms",
+    dependencies=[Depends(require_write)],
+)
+async def batch_delete_alarms(
+    body: dict,
+    db: AsyncSession = Depends(get_db),
+):
+    """批量删除告警记录，最多500条。 / Batch delete alarm records (max 500)."""
+    alarm_ids = body.get("alarm_ids", [])
+    if not alarm_ids:
+        raise HTTPException(status_code=400, detail="alarm_ids is required")
+    if len(alarm_ids) > 500:
+        raise HTTPException(status_code=400, detail="Max 500 records per request")
+    result = await db.execute(
+        select(AlarmRecord).where(AlarmRecord.id.in_(alarm_ids))
+    )
+    records = list(result.scalars().all())
+    for r in records:
+        await db.delete(r)
+    await db.flush()
+    return APIResponse(data={"deleted": len(records)})
+
+
 @router.get(
     "/{alarm_id}",
     response_model=APIResponse[AlarmRecordResponse],