Share songs, albums, movies, shows, podcasts and audiobooks to chat as cards

A share message carries kind, title, subtitle, same-origin art and a hash-route
link, validated on the server. It counts as unread, reads as '🎵 Shared a song:
Title' in pushes and Notifications, and is found by search. In Chat a card opens
the item, or says it is not available when the recipient lacks that tab.

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

public/style.css

@@ -1023,6 +1023,9 @@ body.vizopen { overflow: hidden; }
 .sgopt i { position: absolute; inset: 0 auto 0 0; background: rgba(127,127,127,.25); z-index: 0; } .sgopt span, .sgopt small { position: relative; z-index: 1; } .sgopt span { flex: 1; } .sgopt.on { border-color: currentColor; font-weight: 600; } .sgopt:disabled { cursor: default; opacity: .8; }
 .sgprev { display: flex; gap: 10px; margin: 6px 0 2px; padding: 8px; border-radius: 10px; background: rgba(127,127,127,.18); color: inherit; text-decoration: none; overflow: hidden; } .sgprev img { width: 64px; height: 64px; object-fit: cover; border-radius: 8px; flex: none; }
 .sgprev span { min-width: 0; } .sgprev small, .sgprev b, .sgprev em { display: block; overflow: hidden; text-overflow: ellipsis; } .sgprev small { opacity: .7; } .sgprev b { white-space: nowrap; } .sgprev em { font-style: normal; opacity: .8; font-size: 13px; max-height: 2.6em; }
+.sgshare { display: flex; align-items: center; gap: 10px; margin: 2px 0 4px; padding: 8px; min-width: 220px; border-radius: 12px; background: rgba(127,127,127,.18); color: inherit; text-decoration: none; overflow: hidden; } .sgshare.off { opacity: .75; }
+.sgshare-art { flex: none; width: 56px; height: 56px; border-radius: 8px; object-fit: cover; background: rgba(127,127,127,.25); display: grid; place-items: center; font-size: 26px; font-style: normal; }
+.sgshare-t { min-width: 0; flex: 1; } .sgshare-t small, .sgshare-t b, .sgshare-t em { display: block; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font-style: normal; } .sgshare-t small { opacity: .7; } .sgshare-t em { opacity: .8; font-size: .9em; } .sgshare-t .sgshare-off { opacity: 1; color: var(--danger); font-weight: 600; margin-top: 2px; } .sgshare-go { font-size: 22px; opacity: .6; }
 .chemo { position: absolute; bottom: 100%; left: 0; right: 0; display: grid; grid-template-columns: repeat(auto-fill, minmax(40px, 1fr)); gap: 2px; max-height: 190px; overflow: auto; padding: 8px; background: var(--panel); border: 1px solid var(--line); border-radius: 12px 12px 0 0; z-index: 25; }
 .chemo button { border: 0; background: none; font-size: 24px; padding: 4px; cursor: pointer; border-radius: 8px; } .chemo button:hover { background: var(--panel2); }
 .sgc { position: relative; } .sgc.rec > :not(.chrecbar) { visibility: hidden; } .chrecbar { position: absolute; inset: 0; display: flex; align-items: center; gap: 10px; padding: 0 10px; background: var(--panel); } .recdot { width: 10px; height: 10px; border-radius: 50%; background: var(--danger); animation: chblink 1s infinite; } @keyframes chblink { 50% { opacity: .2; } }