feat(web): match track kebab to Android + add it to full-screen Now Playing

Bring the web TrackMenu to parity with Android's canonical TrackActionsSheet
so the kebab reads the same on both clients:
- Reorder to Android's groups: queue → like/add-to-playlist/start-radio →
  go-to-album/artist → hide.
- Drop the duplicate "Flag this track…" item — it opened the very same
  FlagPopover as "Hide" (Android folds flag into a single Hide).
- Align icons (ListVideo / ListMusic / ListPlus / Disc3 / User).
- Admin-only "Remove from library" stays as a web superset (Android has no
  surface for it), past its own divider.

Mount the kebab on the full-screen /now-playing route with hideQueueActions,
mirroring Android's NowPlayingScreen — Start radio / Add to playlist / Hide
were previously unreachable there (only like + volume + queue existed).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web/src/routes/now-playing/+page.svelte

@@ -16,6 +16,7 @@
   import { FALLBACK_COVER, coverUrl } from '$lib/media/covers';
   import { useSmoothPosition } from '$lib/player/smoothPosition.svelte';
   import LikeButton from '$lib/components/LikeButton.svelte';
+  import TrackMenu from '$lib/components/TrackMenu.svelte';
   import QueueList from '$lib/components/QueueList.svelte';
   import { pageTitle } from '$lib/branding';
 
@@ -78,6 +79,15 @@
       <ArrowLeft size={22} strokeWidth={1.5} />
     </button>
     <div class="ml-2 text-xs uppercase tracking-wide text-text-secondary">Now playing</div>
+    <!-- Full-screen Now Playing carries the same kebab as Android's
+         NowPlayingScreen (hideQueueActions — the menu's track IS the one
+         playing), so Start radio / Add to playlist / Hide etc. are reachable
+         here, not just from the mini-player bar. -->
+    {#if current}
+      <div class="ml-auto">
+        <TrackMenu track={current} hideQueueActions />
+      </div>
+    {/if}
   </header>
 
   {#if !current}