Allow injecting the Codex Apps tools cache (#33113)

## What changed

- Accept a caller-provided `CodexAppsToolsCache` when constructing a `ThreadManager` and pass it through to the MCP manager.
- Add `ConnectorRuntimeManager::new_without_cache()` for an in-memory runtime that neither loads nor persists connector state on disk.
- Re-export `CodexAppsToolsCache` from `codex-core` and `codex-core-api` for embedders.

## Testing

- Verify that a cache-disabled connector runtime ignores existing disk state and publishes live tools without creating cache files.

GitOrigin-RevId: f52f4f27c425a8d84ad0d0987b30a6fc3c14d702

codex-rs/mcp-server/src/message_processor.rs

@@ -76,6 +76,7 @@ impl MessageProcessor {
             config.as_ref(),
             Arc::clone(&auth_manager),
             codex_core::build_models_manager(config.as_ref(), auth_manager),
+            codex_core::CodexAppsToolsCache::default(),
             SessionSource::Mcp,
             environment_manager,
             Arc::new(extensions.build()),