feat: surface structured permission details in approval UI

Wire the sidecar's new permissionDetail payload through the frontend:
- Add PermissionDetail interface to sidecar contract
- Add permissionDetail field to PendingApprovalRecord and thread
  through normalization and AryxAppService mapping
- Create PermissionDetailView component with kind-specific rendering:
  shell (command block + warning), write (filename + diff), read (path),
  mcp (server badge + args), url (prominent URL), memory (subject/fact),
  custom-tool (description + args), hook (message + args)
- ApprovalBanner shows structured detail when available, falls back to
  generic text for backward compatibility
- QueuedApprovalsList shows brief kind-specific summaries

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/main/AryxAppService.ts

@@ -1199,6 +1199,7 @@ export class AryxAppService extends EventEmitter<AppServiceEvents> {
       permissionKind: event.permissionKind,
       title: event.title,
       detail: event.detail,
+      permissionDetail: event.permissionDetail,
     };
   }