feat(web): make TrackRow click-to-play; pass tracks+index from album page

TrackRow becomes a <button> that dispatches playQueue(tracks, index).
Album page supplies the full track list + each index so the rest of
the album enqueues automatically when the user clicks a track.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

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

@@ -69,8 +69,8 @@
       <p class="text-text-secondary">This album has no tracks.</p>
     {:else}
       <div class="overflow-hidden rounded border border-border">
-        {#each album.tracks as track (track.id)}
-          <TrackRow {track} />
+        {#each album.tracks as track, i (track.id)}
+          <TrackRow tracks={album.tracks} index={i} />
         {/each}
       </div>
     {/if}