fix(api): align API layer with backend response formats

- wallet: parse {balance: string} response
- favorites: addFavorite returns void (EmptyResp)
- services: handle paginated response from listServicesByPlayer
- files: use query param ?key= instead of path param /:id
- search: remove unsupported selectedGames/minRating params

lib/api/files.ts

@@ -1,5 +1,5 @@
 export async function getFileById(fileId: string): Promise<Blob> {
-  const res = await fetch(`/api/v1/files/${encodeURIComponent(fileId)}`)
+  const res = await fetch(`/api/v1/files?key=${encodeURIComponent(fileId)}`)
 
   if (res.ok) return await res.blob()