feat(web/m7-363): per-route svelte:head titles for dynamic detail pages

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

@@ -2,6 +2,7 @@
   import { Play } from 'lucide-svelte';
   import { page } from '$app/state';
   import { createArtistQuery } from '$lib/api/queries';
+  import { pageTitle } from '$lib/branding';
   import AlbumCard from '$lib/components/AlbumCard.svelte';
   import LikeButton from '$lib/components/LikeButton.svelte';
   import LibrarySkeleton from '$lib/components/LibrarySkeleton.svelte';
@@ -48,6 +49,10 @@
   }
 </script>
 
+<svelte:head>
+  <title>{pageTitle(query.data?.name ? `Artist · ${query.data.name}` : 'Artist')}</title>
+</svelte:head>
+
 <div class="space-y-4">
   <a href="/" class="text-sm text-text-secondary hover:text-text-primary">← Library</a>