Right panel today has fixed width. Make it resizable using same pattern as #23 (left sidebar).
Implementation:
- Refactor ResizableSidebar → ResizablePanel reusable
- Add side='left' | 'right' prop
- Drag handle on opposite side
- Min 300px, max 50vw, default 400px
- Storage key: deck:rightPanelWidth
- Independent from pin state
Phase 1: simple resize, no collapse on min.
Phase 2 (future): collapse below threshold.
Right panel today has fixed width. Make it resizable using same pattern as #23 (left sidebar).
Implementation:
Phase 1: simple resize, no collapse on min.
Phase 2 (future): collapse below threshold.