feat(voice): add WebRTC voice channels with Cloudflare TURN support

Add voice channel functionality with WebRTC peer-to-peer audio:
- Add VoiceSignalingConsumer for WebRTC signaling and peer coordination
- Add GlobalConsumer for real-time presence and voice status updates
- Add voice channel type to Channel model with current_voice_channel tracking on UserProfile
- Add voice controls UI (mute, deafen, disconnect) in status panel
- Add voice member list display in sidebar with avatar support
- Add

chat/tests.py

@@ -0,0 +1,37 @@
+from django.test import TestCase, Client
+from django.urls import reverse
+from django.contrib.auth.models import User
+from chat.models import Channel
+
+
+class VoiceChannelsTests(TestCase):
+    def setUp(self):
+        self.user = User.objects.create_user(username='testuser', password='password')
+        self.client = Client()
+
+    def test_voice_credentials_anonymous(self):
+        # Anonymous user should be redirected to login
+        url = reverse('voice_credentials')
+        response = self.client.get(url)
+        self.assertEqual(response.status_code, 302)
+
+    def test_voice_credentials_authenticated(self):
+        # Authenticated user should get ICE servers JSON
+        self.client.login(username='testuser', password='password')
+        url = reverse('voice_credentials')
+        response = self.client.get(url)
+        self.assertEqual(response.status_code, 200)
+        data = response.json()
+        self.assertIn('iceServers', data)
+        self.assertTrue(len(data['iceServers']) > 0)
+        self.assertIn('urls', data['iceServers'][0])
+
+    def test_channel_model_default_type(self):
+        # Default channel type should be 'text'
+        channel = Channel.objects.create(name='general', created_by=self.user)
+        self.assertEqual(channel.channel_type, 'text')
+
+    def test_voice_channel_type(self):
+        # Can create channel of type 'voice'
+        channel = Channel.objects.create(name='Gaming', channel_type='voice', created_by=self.user)
+        self.assertEqual(channel.channel_type, 'voice')