- Store: assignToArea now rejects with an error if the target area is the
  last remaining root (parent_id <= 0), preventing zero-root trees.
- UI: AreaDetailPage hides the 'Assign to area' / 'Change parent area'
  button and action-menu item when the current area is the last root,
  and shows an explanatory empty-state message instead.
- Tests: add coverage for both the rejection and the allowed case.

- Extend AreaAssignSection with  and ]2;]1; props for reuse
- Add  to areasStore with reactive splice update
- Rewrite AreaDetailPage with shared useAreaAssign, AreaBadgeLink, AreaAssignSection
- Filter area options to exclude self-reference and descendants
- Add areasStore test for assignToArea
- 126 tests passing, build green

- Add ScriptDetailPage for actions, regular, and scopes
- Add scope field to script API response (from backend)
- Replace scope raw-PHP endpoint with client-side filtering via scope field
- Show action and regular scripts grouped by scope on scope detail page
- Remove inline switch from action cards (moved to detail page)
- Add router-links from list pages to detail pages
- Update MSW mocks with scope field for all script types