Fix bugs, migrate favorites store to Composition API, DRY state loader, add page tests, replace CSS vars with kit classes

Move unassign into a dedicated confirm dialog and fix icon ...

- Revert useAreaAssign composable back to pure assign logic; remove
  submitUnassignCore and unassign state that leaked into the assign modal.
- DeviceDetailPage, ScriptDetailPage, AreaDetailPage:
  * Remove the Unassign button from the assign modal footer.
  * Add a separate GnModal confirm dialog for unassign (like Remove).
  * Dropdown action now opens the confirm dialog instead of firing
    immediately.
  * Replace non-existent ph-map-pin-slash icon with ph-x-circle.

Add unassign action to area, device and script detail pages ...

- useAreaAssign composable: add submitUnassignCore and loading/error states.
- DeviceDetailPage: add 'Unassign from area' button inside assign modal and
  in the actions dropdown when device has an area_id.
- ScriptDetailPage: same for scripts (non-scope) with area_id.
- AreaDetailPage: add 'Unassign from parent' in assign modal and dropdown
  when area has a parent_id > 0.

Use gnexus-ui-kit semantic colors for device status dot and add state components ...

- Status dot in DeviceTable now uses .text-success / .text-danger from
  gnexus-ui-kit with currentColor for background and glow instead of
  project-specific CSS vars.
- Add DeviceChannelsState component for per-channel state rendering.
- Add loadStatesFor helper in devices store for targeted state loading.
- Record styling rule in CLAUDE.md: always prefer kit color classes.

Add toast feedback for device reboot in list and detail views

Fix area assignment button on detail pages ...

- Rename submitAssign -> submitAssignCore in useAreaAssign composable
  to avoid name collision with local page handlers.
- Rename local page handlers -> handleAssignSubmit on Area, Device,
  and Script detail pages so event bindings call the wrapper correctly.
- Fix AppEmptyState.vue to forward #action slot into GnEmptyState's
  #actions slot so the Assign button renders for unassigned items.

Improve AppErrorState with statusCode, type, and copyable details (Phase 4) ...

- Add error prop to AppErrorState accepting normalized client error object
- Show type, statusCode, and errorAlias as inline badges
- Add GnCopyButton to copy JSON-serialized error details to clipboard
- displayMessage falls back to error.message when message prop is omitted
- Update all call sites to pass full error object instead of only .message
- Add tests for error badges, copy button visibility, and clipboard content

Add toast notifications for mutations (Phase 3) ...

- Wrap RouterView in GnToastProvider in App.vue
- Replace inline rebootError alert in DeviceDetailPage with toast
- Replace inline resultAlert in ScriptDetailPage and ScriptsActionsPage with toast
- Add success toasts after successful edit, assign, remove, rename, create, setup
- Keep inline GnAlert inside modals for form-level errors

Fix critical error handling gaps in page mutations ...

- AreaDetailPage: submitRemove now checks result.ok before redirecting;
  replace GnConfirmDialog with GnModal to display remove errors inline.
- DeviceDetailPage: submitRemove now checks result.ok before redirecting;
  replace GnConfirmDialog with GnModal. reboot() now awaits and shows
  error via inline GnAlert instead of silently failing.
- ScriptDetailPage: toggleState now checks result.ok and shows success/
  danger resultAlert feedback instead of ignoring API errors.

All 126 Vitest tests pass.

Pack detail-page header actions into GnDropdown component

Vue client: extract DeviceTable component and use in AreaDetail ...

- Add reusable DeviceTable component (device cell, connect badge, state, reboot)
- Refactor DevicesListPage to use DeviceTable
- Replace simple device table in AreaDetailPage with full DeviceTable
- 126 tests passing, build green

Vue client: add shared area assignment to scripts and devices ...

- Add useAreaAssign composable for reusable area assignment logic
- Add AreaBadgeLink and AreaAssignSection shared components
- Integrate area assignment into ScriptDetailPage (actions/regular)
- Integrate area assignment into DeviceDetailPage
- Update scriptsStore with assignToArea / unassignFromArea + reactivity fixes
- Update API modules: scripts.placeInArea, devices.assignToArea
- Update list views: show area badges in actions/regular cards and tables
- Add tests and mock handlers for script area operations
- Update AppShell nav and routes for detail pages
- Add prism-theme.css for code highlighting
- 125 tests passing, build green

Add script detail pages with scope grouping ...

- 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

Add Vue devices list page