protect mode for kiwi

### Is this a regression?

No

### Description

The kiwi should have a protect mode as Redis to refuse write request.
Fox example when the disk is almost full or the lock is rollback, the leader should be in proect mode.

### Please provide a link to a minimal reproduction of the bug

_No response_

### Screenshots or videos

_No response_

### Please provide the version you discovered this bug in (check about page for version information)

```true

```

### Anything else?

_No response_

No file or test is identified in the issue. Start by tracing leader write-request handling and the existing Redis-compatible behavior, then determine how disk-full and lock-rollback conditions are detected. Done should mean the leader reliably refuses writes while in protect mode, with coverage for those conditions.

Written by the indexing model from the issue text.