Add comprehensive queue management to browser phone shortcode

Features Added:
- Queue display showing all assigned queues for the current user
- Real-time queue statistics (waiting calls, capacity)
- Visual indicators for queues with waiting calls (green border, pulse animation)
- Queue selection with click interaction
- Accept next call from selected queue functionality
- Auto-refresh of queue data every 30 seconds
- Mobile-responsive queue interface

Backend Changes:
- New ajax_get_agent_queues() handler to fetch user's assigned queues
- Enhanced ajax_get_waiting_calls() to return structured data
- Proper permission checking for twp_access_agent_queue capability

Frontend Enhancements:
- Interactive queue list with selection states
- Queue controls panel showing selected queue info
- Refresh button for manual queue updates
- Visual feedback for queues with active calls
- Mobile-optimized layout for smaller screens

UI/UX Improvements:
- Queues with waiting calls highlighted with green accent
- Pulsing indicator for active queues
- Auto-selection of first queue with calls
- Responsive design for mobile devices
- Dark mode support for queue elements

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

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

assets/css/browser-phone-frontend.css

@@ -293,8 +293,8 @@
     font-weight: 500;
 }
 
-/* Queue Controls */
-.twp-queue-controls {
+/* Queue Management Section */
+.twp-queue-section {
     background: #fff;
     padding: 16px;
     border-radius: 8px;
@@ -302,18 +302,148 @@
     margin-bottom: 20px;
 }
 
-.twp-queue-controls h4 {
-    margin: 0 0 12px 0;
+.twp-queue-section h4 {
+    margin: 0 0 16px 0;
     color: #333;
     font-size: 1.1rem;
+    text-align: center;
 }
 
-.queue-status {
-    margin-bottom: 12px;
+/* Queue List */
+.twp-queue-list {
+    margin-bottom: 16px;
+}
+
+.queue-loading,
+.no-queues {
+    text-align: center;
     color: #6c757d;
+    font-style: italic;
+    padding: 20px;
+}
+
+.no-queues {
+    background: #f8f9fa;
+    border: 2px dashed #e9ecef;
+    border-radius: 8px;
+}
+
+.queue-item {
+    background: #f8f9fa;
+    border: 2px solid #e9ecef;
+    border-radius: 8px;
+    padding: 12px;
+    margin-bottom: 8px;
+    cursor: pointer;
+    transition: all 0.2s ease;
+    position: relative;
+}
+
+.queue-item:hover {
+    border-color: #007cba;
+    background: #e3f2fd;
+}
+
+.queue-item.selected {
+    border-color: #007cba;
+    background: #e3f2fd;
+    box-shadow: 0 0 0 1px #007cba;
+}
+
+.queue-item.has-calls {
+    border-left: 4px solid #28a745;
+}
+
+.queue-item.has-calls::after {
+    content: '';
+    position: absolute;
+    top: 8px;
+    right: 8px;
+    width: 8px;
+    height: 8px;
+    background: #28a745;
+    border-radius: 50%;
+    animation: pulse 2s infinite;
+}
+
+.queue-name {
+    font-weight: 600;
+    color: #333;
+    margin-bottom: 4px;
+}
+
+.queue-info {
+    display: flex;
+    justify-content: space-between;
+    align-items: center;
+    font-size: 0.9rem;
+    color: #6c757d;
+}
+
+.queue-waiting {
     font-weight: 500;
 }
 
+.queue-waiting.has-calls {
+    color: #28a745;
+    font-weight: 600;
+}
+
+.queue-capacity {
+    font-size: 0.8rem;
+}
+
+/* Queue Controls */
+.twp-queue-controls {
+    background: #f8f9fa;
+    padding: 16px;
+    border-radius: 8px;
+    border: 2px solid #e9ecef;
+    margin-top: 16px;
+}
+
+.selected-queue-info {
+    margin-bottom: 16px;
+    text-align: center;
+}
+
+.selected-queue-info h5 {
+    margin: 0 0 8px 0;
+    color: #333;
+    font-size: 1rem;
+}
+
+.queue-stats {
+    display: flex;
+    justify-content: center;
+    gap: 20px;
+    font-size: 0.9rem;
+    color: #6c757d;
+}
+
+.queue-stats span {
+    font-weight: 500;
+}
+
+.queue-actions {
+    display: flex;
+    gap: 8px;
+}
+
+.queue-actions .twp-btn {
+    flex: 1;
+}
+
+.twp-btn-secondary {
+    background: #6c757d;
+    color: white;
+}
+
+.twp-btn-secondary:hover {
+    background: #5a6268;
+    transform: translateY(-1px);
+}
+
 /* Messages */
 .twp-messages {
     margin-top: 16px;
@@ -397,6 +527,26 @@
         min-height: 45px;
         font-size: 16px;
     }
+    
+    /* Queue section mobile adjustments */
+    .queue-stats {
+        flex-direction: column;
+        gap: 8px;
+    }
+    
+    .queue-actions {
+        flex-direction: column;
+    }
+    
+    .queue-item {
+        padding: 10px;
+    }
+    
+    .queue-info {
+        flex-direction: column;
+        align-items: flex-start;
+        gap: 4px;
+    }
 }
 
 /* Dark mode support */