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/index.html

@@ -41,7 +41,7 @@
   .profile .pmenu a:hover{background:#f1f5f9}
   .profile .pmenu a.danger{color:#b91c1c;border-top:1px solid #eef1f6}
 </style>
-<script src="/icons.js"></script>
+<script src="/icons.js?v=3"></script>
 </head>
 <body>
 <header>