feat(web/m7-363): per-route svelte:head titles for static routes

Add browser tab titles to all 18 static page routes using the pageTitle()
helper from $lib/branding. Titles follow the Minstrel · Section format.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

web/src/routes/library/hidden/+page.svelte

@@ -1,4 +1,5 @@
 <script lang="ts">
+  import { pageTitle } from '$lib/branding';
   import { Music2, RotateCcw } from 'lucide-svelte';
   import { useQueryClient } from '@tanstack/svelte-query';
   import { createMyQuarantineQuery, unflagTrack } from '$lib/api/quarantine';
@@ -40,6 +41,8 @@
   }
 </script>
 
+<svelte:head><title>{pageTitle('Library · Hidden')}</title></svelte:head>
+
 <div class="space-y-6">
   <header class="space-y-1">
     <h2 class="font-display text-2xl font-medium text-text-primary">Hidden</h2>