Gate Apps usage instructions by model capability (#37145)

## What changed

- Add `include_apps_usage_instructions` to model metadata, defaulting to true for compatibility with existing metadata.
- Emit generic Apps guidance only when apps are available and the selected model enables it.
- Enable the capability for interactive model presets while leaving `codex-auto-review` and local models opted out.

## Testing

- Verify that missing metadata defaults to enabled and an explicit opt-out survives serialization.

GitOrigin-RevId: 6a20573cddfd3b80083d2b4b015829b49e6cc283

codex-rs/codex-api/tests/models_integration.rs

@@ -82,6 +82,7 @@ async fn models_client_hits_models_endpoint() {
             model_messages: None,
             include_skills_usage_instructions: false,
             include_plugin_usage_instructions: false,
+            include_apps_usage_instructions: false,
             supports_reasoning_summary_parameter: true,
             default_reasoning_summary: ReasoningSummary::Auto,
             support_verbosity: false,