- 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.

- 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

- 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

- 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.

- 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