feat: implement ROMs management UI (Phase 8)

Backend (Phase 8.1):
- Add ROMs endpoints: GET, GET/:id, PUT/:id/game, DELETE
- Add metadata search endpoint using IGDB/RAWG/TGDB
- Implement RomsController with ROM CRUD logic
- Add 12 comprehensive ROM endpoint tests
- Configure Vitest to run tests sequentially (threads: false)
- Auto-apply Prisma migrations in test setup

Frontend (Phase 8.2 + 8.3):
- Create ROM types: RomFile, Artwork, EnrichedGame
- Extend API client with roms and metadata namespaces
- Implement 5 custom hooks with TanStack Query
- Create ScanDialog, MetadataSearchDialog, RomCard components
- Rewrite roms.tsx page with table and all actions
- Add 37 comprehensive component and page tests

All 122 tests passing: 63 backend + 59 frontend
Lint: 0 errors, only unused directive warnings

frontend/src/lib/api.ts

@@ -1,4 +1,5 @@
 import { Game, CreateGameInput, UpdateGameInput } from '../types/game';
+import { RomFile, EnrichedGame, ScanResult } from '../types/rom';
 
 const API_BASE = '/api';
 
@@ -36,4 +37,28 @@ export const api = {
         method: 'DELETE',
       }),
   },
+
+  roms: {
+    list: () => request<RomFile[]>('/roms'),
+    getById: (id: string) => request<RomFile>(`/roms/${id}`),
+    linkGame: (romId: string, gameId: string) =>
+      request<RomFile>(`/roms/${romId}/game`, {
+        method: 'PUT',
+        body: JSON.stringify({ gameId }),
+      }),
+    delete: (id: string) => request<void>(`/roms/${id}`, { method: 'DELETE' }),
+  },
+
+  metadata: {
+    search: (query: string) =>
+      request<EnrichedGame[]>('/metadata/search?q=' + encodeURIComponent(query)),
+  },
+
+  import: {
+    scan: (dir: string) =>
+      request<ScanResult>('/import/scan', {
+        method: 'POST',
+        body: JSON.stringify({ dir }),
+      }),
+  },
 };