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/sw.js

@@ -15,8 +15,8 @@ self.addEventListener('push', (event) => {
   const title = d.title || 'Biz Connect';
   const options = {
     body: d.body || '',
-    icon: '/logo.png',
-    badge: '/logo.png',
+    icon: d.icon || '/icon-192.png',  // sender/group DP when the server provides one, else brand icon (not the old wordmark)
+    badge: '/icon-192.png',
     tag: d.tag || undefined,        // collapse repeats from the same chat
     renotify: !!d.tag,
     data: { kind: d.kind || '', id: d.id || '' },