Add comprehensive voicemail integration to browser phone

- Add AJAX endpoint for fetching user voicemails with stats and recent list
- Create voicemail display section with counts, transcriptions, and playback
- Implement click-to-play functionality for voicemail audio
- Add refresh and view-all buttons with admin page integration
- Style voicemail section with consistent design and dark mode support
- Include visual indicators for recordings and formatted durations
- Add mobile responsive design and hover effects

🤖 Generated with [Claude Code](https://claude.ai/code)

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

assets/css/browser-phone-frontend.css

@@ -463,6 +463,148 @@
     opacity: 0.8;
 }
 
+/* Voicemail Section */
+.twp-voicemail-section {
+    background: #fff;
+    padding: 16px;
+    border-radius: 8px;
+    border: 2px solid #e9ecef;
+    margin-bottom: 20px;
+}
+
+.twp-voicemail-section h4 {
+    margin: 0 0 16px 0;
+    color: #212529;
+    font-size: 1.1rem;
+    text-align: center;
+}
+
+.voicemail-stats {
+    display: flex;
+    justify-content: space-around;
+    margin-bottom: 16px;
+    padding: 12px;
+    background: #f8f9fa;
+    border-radius: 6px;
+}
+
+.stat-item {
+    text-align: center;
+}
+
+.stat-label {
+    display: block;
+    font-size: 0.9rem;
+    color: #6c757d;
+    margin-bottom: 4px;
+}
+
+.stat-value {
+    display: block;
+    font-size: 1.2rem;
+    font-weight: 600;
+    color: #495057;
+}
+
+.twp-voicemail-list {
+    margin-bottom: 16px;
+    max-height: 200px;
+    overflow-y: auto;
+}
+
+.voicemail-item {
+    padding: 12px;
+    border: 1px solid #dee2e6;
+    border-radius: 6px;
+    margin-bottom: 8px;
+    cursor: pointer;
+    transition: all 0.2s ease;
+}
+
+.voicemail-item:hover {
+    background: #f8f9fa;
+    border-color: #007bff;
+}
+
+.voicemail-item.has-recording {
+    border-left: 4px solid #28a745;
+}
+
+.voicemail-header {
+    display: flex;
+    justify-content: space-between;
+    align-items: center;
+    margin-bottom: 8px;
+}
+
+.voicemail-from {
+    display: flex;
+    align-items: center;
+    gap: 6px;
+}
+
+.from-number {
+    font-weight: 600;
+    color: #495057;
+}
+
+.voicemail-time {
+    font-size: 0.85rem;
+    color: #6c757d;
+}
+
+.voicemail-details {
+    display: flex;
+    align-items: center;
+    gap: 12px;
+    margin-bottom: 8px;
+}
+
+.voicemail-duration {
+    display: flex;
+    align-items: center;
+    gap: 4px;
+    font-size: 0.9rem;
+    color: #6c757d;
+}
+
+.recording-indicator {
+    background: #28a745;
+    color: white;
+    padding: 2px 8px;
+    border-radius: 12px;
+    font-size: 0.8rem;
+}
+
+.voicemail-transcription {
+    font-size: 0.9rem;
+    color: #495057;
+    font-style: italic;
+    padding: 8px;
+    background: #f8f9fa;
+    border-radius: 4px;
+    border-left: 3px solid #007bff;
+}
+
+.voicemail-actions {
+    display: flex;
+    gap: 8px;
+    flex-wrap: wrap;
+}
+
+.voicemail-actions .twp-btn {
+    flex: 1;
+    min-width: 80px;
+}
+
+.no-voicemails,
+.voicemail-loading {
+    text-align: center;
+    padding: 20px;
+    color: #6c757d;
+    font-style: italic;
+}
+
 .twp-btn-secondary {
     background: #6c757d;
     color: white;
@@ -588,7 +730,8 @@
     .twp-connection-status,
     .twp-call-info,
     .twp-queue-controls,
-    .twp-queue-section {
+    .twp-queue-section,
+    .twp-voicemail-section {
         background: #2d3748;
         border-color: #4a5568;
     }
@@ -623,8 +766,11 @@
     .twp-phone-selection label,
     .twp-browser-phone-title,
     .twp-queue-section h4,
+    .twp-voicemail-section h4,
     .selected-queue-info h5,
-    .timer-value {
+    .timer-value,
+    .from-number,
+    .stat-value {
         color: #f7fafc;
     }
     
@@ -635,14 +781,33 @@
     .queue-info,
     .queue-stats,
     .queue-loading,
-    .no-queues {
+    .no-queues,
+    .voicemail-stats,
+    .voicemail-time,
+    .voicemail-duration,
+    .stat-label,
+    .voicemail-loading,
+    .no-voicemails {
         color: #cbd5e0;
     }
     
-    .no-queues {
+    .no-queues,
+    .voicemail-stats,
+    .voicemail-transcription {
         background: #2d3748;
         border-color: #4a5568;
     }
+    
+    .voicemail-item {
+        background: #2d3748;
+        border-color: #4a5568;
+        color: #f7fafc;
+    }
+    
+    .voicemail-item:hover {
+        background: #4a5568;
+        border-color: #63b3ed;
+    }
 }
 
 /* Animation for incoming calls */