feat: the Wanted view becomes Collection, shaped like Lidarr: an artist catalogue first, the state sections down a left rail (M502 #5577)

The section opens on a catalogue of every artist on the list, A–Z with a
letter rail, each card showing how many of their albums are held. An artist
opens on their page: every album of theirs, held or not, with its status,
search, releases and tracks. Wanted, Missing files, Activity, Following and
Blocked sit down a left rail as the sections that show state; Held is gone,
the catalogue shows it. The section moves from /wanted to /collection.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/src/lib/components/Shell.svelte

@@ -1,7 +1,7 @@
 <script lang="ts">
   import { page } from '$app/state';
   import { goto } from '$app/navigation';
-  import { ChevronDown, Compass, House, LibraryBig, ListChecks } from 'lucide-svelte';
+  import { ChevronDown, Compass, Disc3, House, LibraryBig } from 'lucide-svelte';
   import { user, logout } from '#lib/auth/store.svelte.js';
   import { player } from '#lib/player/store.svelte.js';
   import { appName } from '#lib/branding.js';
@@ -52,13 +52,14 @@
   // bounce through the /library 308-redirect. isActive('/library')
   // still matches all sub-routes by prefix so the active state covers
   // every tab.
-  // Wanted (M502) is an admin's: what Minstrel is fetching for the library.
+  // Collection (M502) is an admin's: the catalogue of what the library holds
+  // and wants, and what Minstrel is fetching for it, shaped like Lidarr's.
   const navItems = $derived([
     { href: '/',                 label: 'Home',     icon: House,       matchPrefix: '/' },
     { href: '/library/artists',  label: 'Library',  icon: LibraryBig,  matchPrefix: '/library' },
     { href: '/discover',         label: 'Discover', icon: Compass,     matchPrefix: '/discover' },
     ...(user.value?.is_admin
-      ? [{ href: '/wanted',      label: 'Wanted',   icon: ListChecks,  matchPrefix: '/wanted' }]
+      ? [{ href: '/collection',  label: 'Collection', icon: Disc3,   matchPrefix: '/collection' }]
       : [])
   ]);
 </script>