feat(modal): add rollout telemetry foundation

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

assets/js/routes/user-center-auth.js

@@ -63,8 +63,20 @@
     var currentUuid = config.currentUuid || '';
     var pollTimer = null;
     var shouldPoll = false;
+    var telemetry = window.AksrtModalTelemetry;
+    var telemetryId = '';
 
-    function open() { modal.classList.add('is-open'); modal.setAttribute('aria-hidden', 'false'); document.body.style.overflow = 'hidden'; }
+    function telemetryMark(event) {
+      if (telemetry && telemetryId && typeof telemetry.mark === 'function') telemetry.mark(telemetryId, event);
+    }
+
+    function open() {
+      telemetryId = telemetry && typeof telemetry.start === 'function' ? telemetry.start('identity') : '';
+      modal.classList.add('is-open');
+      modal.setAttribute('aria-hidden', 'false');
+      document.body.style.overflow = 'hidden';
+      telemetryMark('shell');
+    }
     function close() { modal.classList.remove('is-open'); modal.setAttribute('aria-hidden', 'true'); document.body.style.overflow = ''; }
     root.querySelectorAll('[data-auth-modal-open]').forEach(function (button) { button.addEventListener('click', open); });
     modal.querySelectorAll('[data-auth-modal-close]').forEach(function (button) { button.addEventListener('click', close); });
@@ -80,6 +92,7 @@
 
     function render(data) {
       if (!data) return;
+      telemetryMark('first-content');
       currentUuid = data.uuid || currentUuid;
       if (statusBox) statusBox.hidden = false;
       if (createForm) createForm.hidden = true;
@@ -102,6 +115,7 @@
       } else {
         stopPolling();
       }
+      telemetryMark('ready');
     }
 
     function refresh() {