Add FCM push notifications, queue alerts, caller ID fixes, and auto-revert agent status

Server-side:
- Add push credential auto-creation for FCM incoming call notifications
- Add queue alert FCM notifications (data-only for background delivery)
- Add queue alert cancellation on call accept/disconnect
- Fix caller ID to show caller's number instead of Twilio number
- Fix FCM token storage when refresh_token is null
- Add pre_call_status tracking to revert agent status 30s after call ends
- Add SSE fallback polling for mobile app connectivity

Mobile app:
- Add Android telecom permissions and phone account registration
- Add VoiceFirebaseMessagingService for incoming call push handling
- Add insistent queue alert notifications with custom sound
- Fix caller number display on active call screen
- Add caller ID selection dropdown on dashboard
- Add phone numbers endpoint and provider support
- Add unit tests for CallInfo, QueueState, and CallProvider
- Remove local.properties from tracking, add .gitignore

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

includes/class-twp-activator.php

@@ -479,7 +479,13 @@ class TWP_Activator {
         if (empty($auto_busy_at_exists)) {
             $wpdb->query("ALTER TABLE $table_agent_status ADD COLUMN auto_busy_at datetime DEFAULT NULL AFTER logged_in_at");
         }
-        
+
+        // Add pre_call_status column to store status before a call set agent to busy
+        $pre_call_exists = $wpdb->get_results("SHOW COLUMNS FROM $table_agent_status LIKE 'pre_call_status'");
+        if (empty($pre_call_exists)) {
+            $wpdb->query("ALTER TABLE $table_agent_status ADD COLUMN pre_call_status varchar(20) DEFAULT NULL AFTER auto_busy_at");
+        }
+
         $table_schedules = $wpdb->prefix . 'twp_phone_schedules';
         
         // Check if holiday_dates column exists