feat: live presence, delivery-tick sync, brand rollout, call fixes, desktop 0.1.3

Live presence (fixes stale in-call/status until refresh — impossible in apps):
- server broadcasts a user's status over the chat socket on connect/disconnect, call
  join/leave, and status change (chat.js broadcastPresence; signaling + routes hooks).
- client onPresence() updates the contact dot + open-chat header live.

Chat delivery ticks (#6): chat-list row now mirrors the thread (delivered→double grey,
read→blue) via a new 'with' field on the delivered relay + onChatRead/onChatDelivered.

Call fixes: no bogus 'host handed over' when a 1:1 call ends (leaveMeeting forced);
branded call-connecting + chat-thread loaders; header subtitle tracks live call state.

Notifications: web notify + sw.js use sender/group DP + brand icon (not old wordmark);
desktop shell drops Web Push so only the single native toast fires (#5).

Brand: master icon/splash/loaders wired everywhere (PWA/favicon/apple-touch/.ico),
branded login (blue + gold CTA), branded toasts (BZToast) on all pages, Electron splash.

Desktop: dev auto-targets localhost (packaged→prod); version 0.1.3 with new multi-size
icon; dropped unused node-notifier; removed home-mockup.html.

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

server/public/host.html

@@ -4,6 +4,10 @@
 <meta charset="UTF-8">
 <meta name="viewport" content="width=device-width, initial-scale=1">
 <title>Browser Host — Remote Access</title>
+<meta name="theme-color" content="#1F3B73">
+<link rel="icon" href="/favicon.ico?v=3" sizes="any">
+<link rel="icon" type="image/png" sizes="32x32" href="/favicon-32.png?v=3">
+<link rel="apple-touch-icon" href="/apple-touch-icon-180.png?v=3">
 <style>
   body { font-family: system-ui, sans-serif; background:#0f172a; color:#e2e8f0; margin:0; padding:1.5rem; }
   .card { max-width:560px; margin:0 auto; background:#1e293b; border-radius:12px; padding:1.5rem; }