Pass full browser_snapshot result when using selector (or add browser_click_by_selector)

When the MCP tool browser_snapshot (cursor-ide-browser) is called with the selector parameter, the response is already limited to one element/subtree and is small in size. Currently only metadata (title, url) is passed into the model context, so we cannot get the element ref and call browser_click.

Suggested fixes:

• (A) When browser_snapshot is called with selector, pass the full response body (the subtree with ref) to the model instead of truncating it.

• (B) Add a tool browser_click_by_selector(selector) so the model can click by CSS selector without needing a ref from the snapshot.

• (C) Optionally write the snapshot to a file in the project and return only the file path in the tool response; the model can then read_file, find the ref, and call browser_click.