feat(voice): WhatsApp Cloud Calling — UI [6] (#14346)

## Summary

Frontend for WhatsApp Cloud Calling: header / contact-panel call
buttons, ringing widget, accept/reject/hangup, mute, in-bubble audio
player + transcript, recording-on-hangup upload, mid-call reload
warning. WebRTC is browser-direct to Meta — no media server bridge.

## Closes
- https://linear.app/chatwoot/issue/PLA-150

## How to test

Requires backend support — the controller, services, model changes, and
routes ship in **#14334** (`feature/pla-150`). Merge / deploy that first
(or simultaneously); the FE alone won't function without those
endpoints.

Then on staging, for a WhatsApp Cloud + embedded-signup inbox with the
new \`Configuration → Enable voice calling\` toggle ON and webhook
registered:

1. **Outbound** — open a conversation, click the phone icon in the
conversation header (or contact panel), grant mic, your phone rings,
answer, audio both ways, hang up. Recording + transcript land in the
bubble within ~10s.
2. **Inbound** — call the business number from your phone. The
FloatingCallWidget appears bottom-right with caller name. Click accept,
audio both ways, hang up. Recording + transcript appear.
3. **Mute** — during an active WhatsApp call, click the mic icon next to
hangup. Speech stops reaching Meta until you click again.
4. **Mid-call reload guard** — try `Cmd-R` during an active call;
browser shows a confirm prompt.

---------

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Co-authored-by: iamsivin <iamsivin@gmail.com>
Co-authored-by: Sivin Varghese <64252451+iamsivin@users.noreply.github.com>

app/javascript/dashboard/components/ChannelSelector.vue

@@ -24,6 +24,10 @@ defineProps({
     type: Boolean,
     default: false,
   },
+  hasVoiceBadge: {
+    type: Boolean,
+    default: false,
+  },
 });
 
 const { t } = useI18n();
@@ -38,10 +42,18 @@ const { t } = useI18n();
       'cursor-not-allowed disabled:opacity-80': isComingSoon,
     }"
   >
-    <div
-      class="flex size-10 items-center justify-center rounded-full bg-n-alpha-2"
-    >
-      <Icon :icon="icon" class="text-n-slate-10 size-6" />
+    <div class="relative">
+      <div
+        class="flex size-10 items-center justify-center rounded-full bg-n-alpha-2"
+      >
+        <Icon :icon="icon" class="text-n-slate-10 size-6" />
+      </div>
+      <div
+        v-if="hasVoiceBadge"
+        class="absolute -top-1 ltr:-right-1 rtl:-left-1 flex size-4 items-center justify-center rounded-full bg-n-alpha-2 ring-2 ring-n-solid-1"
+      >
+        <Icon icon="i-lucide-audio-lines" class="text-n-slate-10 size-2.5" />
+      </div>
     </div>
 
     <div class="flex flex-col items-start gap-1.5">