fix(modal): use 'import type' for TypeScript type-only imports

Vite strips TypeScript types at runtime, so IndexingPhase and IndexingStats
must be imported with 'import type' to avoid runtime errors.

Author: DevanshuNEU

frontend/src/components/IndexingProgressModal.tsx

@@ -18,7 +18,9 @@ import {
   RefreshCw
 } from 'lucide-react'
 import { 
-  useRepoIndexingWebSocket, 
+  useRepoIndexingWebSocket
+} from '@/hooks/useRepoIndexingWebSocket'
+import type { 
   IndexingPhase,
   IndexingStats 
 } from '@/hooks/useRepoIndexingWebSocket'