Cowork: Allow setting a default workspace folder to auto-mount on launch

Feature Request

Is your feature request related to a problem?
Every time I launch a Cowork session, I have to manually select my workspace folder from the dropdown. Since I always mount the same folder (~/), this extra step adds friction to every session start.

Describe the solution you'd like
Add a setting (in Cowork preferences or Claude Desktop settings) to designate a default workspace folder that auto-mounts when a new Cowork session begins. This could be as simple as a "Set as default" option next to recent folders, or a toggle like "Always mount last used folder."

Describe alternatives you've considered

• Using the "Recent Folders" list (current workaround — still requires a click each session)
• Command-line launch flags (not available for Claude Desktop)

Additional context
Power users who always work from the same root folder (e.g., home directory) would benefit from skipping the folder selection step entirely. This is a small UX improvement that reduces friction for daily Cowork usage.

Environment

• macOS (Mac Studio)
• Claude Desktop (Cowork mode, research preview)
• Plan: Max