In monitor page, monitors can not filter by status?

**Describe the bug**
In monitor page, I can not filter monitors by status.

**Database**
- sqlite

**To Reproduce**
Steps to reproduce the behavior:
1. Go to monitor(ip:8383/monitors), now we can see all monitors, some up, some down
2. Choose status-up, we had all monitors, including up/down. But choose status-down, we got nothing

**Expected behavior**
We can filter monitors by status.

**Screenshots**
Here is status-all:

Here is status: up

And here is status:down

**Additional context**
I am using peekaping in docker, and all my monitors are sync to peekaping from api.

Thanks!

The monitor page is at /monitors (likely served by a Go backend). Look for the handler that renders this page and processes filter parameters (status-up, status-down). The bug is likely in the SQL query or filter logic where the 'down' status filter returns nothing. Check the database schema for monitor status fields and the frontend code that sends the filter request. Verify the filter works by testing with both up and down monitors.

索引モデルが issue の本文から書いたものです。