fix: detect atomic passkey counter anomalies (Closes #641)

frontend/security-center.js

@@ -128,6 +128,7 @@
       }
       const labels = {
         sign_in: 'Signed in', sign_out: 'Signed out', passkey_enrolled: 'Passkey enrolled',
+        passkey_counter_anomaly: 'Passkey counter anomaly',
         device_revoked: 'Device access revoked', all_sessions_revoked: 'All device access revoked',
         issue_closed: 'Issue closed', pull_merged: 'Pull request merged',
         pull_review_approved: 'Pull request approved',
@@ -141,6 +142,9 @@
         const details = root.document.createElement('span');
         details.className = 'small muted';
         const context = [event.device_label, event.method, event.target,
+          event.kind === 'passkey_counter_anomaly'
+            ? 'Remove and re-enroll this passkey if the alert repeats'
+            : null,
           event.status === 'pending' ? 'Outcome confirmation pending' : null]
           .filter(value => typeof value === 'string' && value).join(' · ');
         details.textContent = `${new Date(event.created_at * 1000).toLocaleString()}${context ? ' · ' + context : ''}`;