[feat]: Allow terminal panel to be closed or collapsed #529
Description
Feature Summary
Add ability to close or collapse the terminal panel in the workspace view. Currently it's always visible and takes up space even when not needed.
Problem or Use Case
The terminal panel:
- Cannot be closed or minimized
- Takes up vertical/horizontal space constantly
- Often sits idle when not actively being used
- Reduces available space for code diff viewer and other panels
Users who don't frequently interact with terminal output want to reclaim this screen real estate.
Proposed Solution
Add close/collapse controls to terminal panel:
- Close button (X) in panel header → completely hides terminal
- Collapse button (chevron) → minimizes to title bar only
- Keyboard shortcut: Cmd+J to toggle terminal (common in editors)
- Re-open: Menu option or shortcut to restore when closed
Alternatives Considered
- Resizable panel: Still takes minimum space, doesn't solve "hide completely" need
- Detached terminal window: Over-engineered, just need hide/show
Additional Context
Similar to VS Code's integrated terminal (Cmd+J to toggle). Should persist state (closed/open/height) across sessions.