Function createExtensionRunner

createExtensionRunner(webviewPanel: WebviewPanel): Promise<Runner>
Creates a Runner instance for extension-side tool execution.

The Runner uses a smart executor that:
- Executes VS Code-specific operations locally (they need VS Code APIs).
- Bridges notebook/lexical operations to webview (they need document state).
Parameters
- webviewPanel: WebviewPanel
  VS Code webview panel for message communication.
Returns Promise<Runner>
Promise resolving to Runner instance configured with smart executor.
- Defined in src/tools/core/runnerSetup.ts:129