/chronicle reindex queues remote backfill despite local-only remote settings

### Describe the bug

In GitHub Copilot CLI 1.0.61, `/chronicle reindex` still queues sessions for remote backfill and reports session failures even when local-only settings are configured.

The CLI settings include:

```
"remote": "off",
"remoteExport": false
```

Despite this, reindex reports remote backfill and logs show remote session creation attempts failing with 403/policy-blocked errors.

### Affected version

GitHub Copilot CLI 1.0.61

### Steps to reproduce the behavior

1. Configure Copilot CLI settings:

```json
{
"remote": "off",
"remoteExport": false,
"memory": true,
"experimental": true
}
```

2. Restart Copilot CLI.
3. Run:

```
/chronicle reindex
```

4. Observe output similar to:

```
Reindex completed with errors: 33 sessions indexed locally, 218 queued for backfill. Errors: 24 session(s) failed
```

5. Inspect recent logs and observe remote session creation attempts/failures such as:

```
Failed to create Mission Control session: 403
RemoteSessionExporter
policy_blocked
Remote sessions are not enabled
```

Additional observation: launching with:

```
copilot --no-remote
```

appears to suppress the remote session startup/Mission Control failure path.

### Expected behavior

With `remote` set to `"off"` and `remoteExport` set to false, `/chronicle reindex` should run in local-only mode and should not queue remote backfill.

If remote/session cloud policy is disabled, the CLI should skip remote backfill cleanly or show a clear policy message without reporting local reindex as completed with remote backfill errors.

### Additional context

Cloud/session policy appears to block remote session creation in this environment, which is expected from the organization policy side. The issue is that local-only settings do not appear to prevent `/chronicle reinde`x from attempting or queuing remote backfill.

Question: is /chronicle reindex expected to ignore `remote: "off"` and `remoteExport: false`? If so, what is the supported way to run Chronicle reindex strictly locally?

Start by reproducing `/chronicle reindex` with `remote: "off"` and `remoteExport: false`, then inspect the recent logs for RemoteSessionExporter and policy-blocked session creation. Compare the result with `copilot --no-remote`; done means local indexing does not queue remote backfill or report remote failures.

Scritto dal modello di indicizzazione a partire dal testo della issue.