Fix browser phone init not starting on mobile (window.load not firing)

The window.load event was never firing on mobile tablets, preventing
the browser phone from initializing. Changed to poll for Twilio SDK
availability instead of waiting for window.load event.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

admin/class-twp-admin.php

@@ -7016,7 +7016,8 @@ class TWP_Admin {
                 <div class="phone-interface">
                     <div class="phone-display">
                         <div id="phone-status">Ready</div>
-                        <div id="device-connection-status" style="font-size: 12px; color: #999; margin-top: 5px;">Connecting...</div>
+                        <div id="device-connection-status" style="font-size: 12px; color: #999; margin-top: 5px;">Loading...</div>
+                        <div id="twp-debug-info" style="font-size: 10px; color: #666; margin-top: 3px;"></div>
                         <div id="phone-number-display"></div>
                         <div id="call-timer" style="display: none;">00:00</div>
                     </div>
@@ -7674,6 +7675,7 @@ class TWP_Admin {
                 
                 // Initialize the browser phone
                 function initializeBrowserPhone() {
+                    debugLog('initializeBrowserPhone called');
                     $('#phone-status').text('Initializing...');
                     updateConnectionStatus('connecting');
 
@@ -7751,13 +7753,16 @@ class TWP_Admin {
                 }
 
                 async function setupTwilioDevice(token) {
+                    debugLog('setupTwilioDevice called');
                     try {
                         // Check if Twilio SDK is available
+                        debugLog('Twilio check: ' + (typeof Twilio) + ', Device: ' + (typeof Twilio !== 'undefined' ? typeof Twilio.Device : 'N/A'));
                         if (typeof Twilio === 'undefined' || !Twilio.Device) {
                             throw new Error('Twilio Voice SDK not loaded');
                         }
 
                         console.log('Setting up Twilio Device...');
+                        debugLog('Creating Twilio.Device...');
                         updateConnectionStatus('connecting');
 
                         // Request media permissions before setting up device
@@ -7807,11 +7812,13 @@ class TWP_Admin {
                         });
 
                         console.log('Twilio Device created with audio constraints:', audioConstraints);
-                        
+                        debugLog('Device created, setting up handlers...');
+
                         // Set up event handlers BEFORE registering
                         // Device registered and ready
                         device.on('registered', function() {
                             console.log('Device registered successfully');
+                            debugLog('Device REGISTERED!');
                             $('#phone-status').text('Ready').css('color', '#4CAF50');
                             $('#call-btn').prop('disabled', false);
                             updateConnectionStatus('connected');
@@ -7893,10 +7900,13 @@ class TWP_Admin {
                         });
                         
                         // Register device AFTER setting up event handlers
+                        debugLog('Calling device.register()...');
                         await device.register();
-                        
+                        debugLog('device.register() completed');
+
                     } catch (error) {
                         console.error('Error setting up Twilio Device:', error);
+                        debugLog('ERROR: ' + error.message);
                         showError('Failed to setup device: ' + error.message);
                     }
                 }
@@ -8232,17 +8242,51 @@ class TWP_Admin {
                     }
                 });
                 
+                // Debug helper
+                function debugLog(msg) {
+                    console.log('TWP Debug: ' + msg);
+                    var debugEl = $('#twp-debug-info');
+                    if (debugEl.length) {
+                        debugEl.append(msg + '<br>');
+                    }
+                }
+
                 // Check if SDK loaded and initialize
+                debugLog('jQuery ready');
+
+                // Don't wait for window.load - it may not fire on mobile
+                // Instead, poll for Twilio SDK availability
+                var sdkCheckAttempts = 0;
+                var maxSdkCheckAttempts = 50; // 5 seconds max
+
+                function checkAndInitialize() {
+                    sdkCheckAttempts++;
+                    debugLog('SDK check #' + sdkCheckAttempts + ': ' + (typeof Twilio));
+
+                    if (typeof Twilio !== 'undefined' && Twilio.Device) {
+                        console.log('Twilio SDK loaded successfully');
+                        debugLog('SDK OK, initializing...');
+                        initializeBrowserPhone();
+                    } else if (sdkCheckAttempts < maxSdkCheckAttempts) {
+                        // Keep checking every 100ms
+                        setTimeout(checkAndInitialize, 100);
+                    } else {
+                        showError('Twilio Voice SDK failed to load. Please check your internet connection and try refreshing the page.');
+                        console.error('Twilio SDK not found after ' + sdkCheckAttempts + ' attempts.');
+                        debugLog('SDK FAILED after ' + sdkCheckAttempts + ' attempts');
+                    }
+                }
+
+                // Start checking after a brief delay
+                setTimeout(checkAndInitialize, 500);
+
+                // Also keep the window.load as backup for desktop
                 $(window).on('load', function() {
-                    setTimeout(function() {
+                    debugLog('Window loaded (backup)');
-                        if (typeof Twilio === 'undefined') {
+                    if (typeof Twilio !== 'undefined' && !device) {
-                            showError('Twilio Voice SDK failed to load. Please check your internet connection and try refreshing the page.');
+                        debugLog('Backup init triggered');
-                            console.error('Twilio SDK not found. Script may be blocked or failed to load.');
+                        initializeBrowserPhone();
-                        } else {
+                    }
-                            console.log('Twilio SDK loaded successfully');
-                            initializeBrowserPhone();
-                        }
-                    }, 1000);
                 });
                 
                 // Clean up on page unload