fix(icons): proper end-call (hang-up) glyph + cache-bust icons.js (v3)

- callEnd is now a rotated-handset hang-up icon (was a phone-off placeholder).
- All pages reference /icons.js?v=3 so browsers/proxies fetch the corrected
  file instead of a stale cached copy (fixes 'old end icon' + icons not
  appearing until a re-render when an old/404 icons.js was cached).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

server/public/host.html

@@ -19,7 +19,7 @@
   .indicator { position:fixed; bottom:0; left:0; right:0; background:#b91c1c; color:#fff; text-align:center; padding:.4rem; font-size:.85rem; display:none; }
   .indicator.show { display:block; }
 </style>
-<script src="/icons.js"></script>
+<script src="/icons.js?v=3"></script>
 </head>
 <body>
 <div class="card">