refactor(web/api): errCode + errMessage helpers; 41 sites migrated (W1)

web/src/routes/albums/[id]/+page.svelte

@@ -15,6 +15,7 @@
   import { playQueue } from '$lib/player/store.svelte';
   import { user } from '$lib/auth/store.svelte';
   import { refetchAlbumCover } from '$lib/api/admin';
+  import { errCode } from '$lib/api/errors';
   import { useQueryClient } from '@tanstack/svelte-query';
 
   const id = $derived(page.params.id ?? '');
@@ -78,7 +79,8 @@
       await refetchAlbumCover(data.id);
       await queryClient.invalidateQueries({ queryKey: qk.album(data.id) });
     } catch (e) {
-      refetchError = (e as { code?: string })?.code ?? 'refetch failed';
+      const code = errCode(e);
+      refetchError = code === 'unknown' ? 'refetch failed' : code;
     } finally {
       refetching = false;
     }