Feature request: add setting to disable mouse tracking

Problem

In fullscreen TUI mode, Claude Code enables terminal mouse tracking so that clicks can select options in dialogs. This causes accidental selections: clicking anywhere in the terminal (e.g. to focus the window, or to scroll) can trigger an unintended option selection in a visible dialog prompt.

Expected behaviour

A setting (e.g. "mouseTrackingEnabled": false in settings.json) that disables mouse click capture while preserving keyboard navigation (arrow keys + Enter).

Steps to reproduce

1. Run Claude Code with "tui": "fullscreen" in settings.
2. Wait for any permission/option dialog to appear.
3. Click somewhere in the terminal that happens to be under an option.
4. The option is selected without the user intending it.

Workaround

None currently. The settings schema has no mouse-related toggle.