VS Code extension doesn't watch for external file edits (--watch flag not exposed)

## Problem When a `.py` marimo notebook is edited externally (e.g., from another editor, AI coding assistant, or script), the VS Code Marimo extension does not detect the change and does not re-run affected cells. The `marimo edit --watch` flag achieves exactly this behavior from the terminal — it monitors the file on disk and hot-reloads changed cells when the file is saved from any external editor. ## Expected behavior The VS Code extension should either: 1. Expose a "Watch mode" toggle that passes `--watch` to the underlying Marimo server, **or** 2. Automatically watch the open `.py` file for external changes and sync the notebook state ## Current workaround Use the terminal instead of the extension: ```bash uvx marimo edit notebook.py --sandbox --watch ``` Then open the browser URL shown in the terminal. ## Use case This is particularly useful when working with AI coding assistants (like GitHub Copilot) that edit the .py file directly — the extension doesn't reflects those changes without a manual restart.