[Feature]: Collapse the Keyboard Shortcuts panel by default in the labeler

[calebrob6]

Problem Statement

The Keyboard Shortcuts panel in the labeling view is expanded by default and occupies a considerable portion of the screen, reducing the space available for the map and labeling work.

Proposed Solution

Start the Keyboard Shortcuts panel collapsed by default. Users can expand it on demand, and ideally the expanded/collapsed state persists across sessions.

Alternatives Considered

• Move shortcuts into a modal or tooltip triggered by a ? key or help icon.
• Auto-collapse after first use rather than defaulting to collapsed.

Area

Frontend (React UI)

Additional Context

Raised as non-blocking UX feedback by Marcelo (@madpsys) on #106 (feat(ui): improve labeling map controls).

Checklist

• I have searched existing issues and this has not already been requested.