[grade=B] feat(auth): onboard missing credentials into encrypted vault

status/js/totp-auth.js

@@ -90,11 +90,22 @@
     errorEl.textContent = 'Verifying...';
     errorEl.className = 'totp-error verifying';
 
+    const redirect = safeSessionGet('totp_redirect');
+    let serviceId = null;
+    if (redirect) {
+      try {
+        const parsed = new URL(redirect, window.location.origin);
+        const suffix = SITE.tld.startsWith('.') ? SITE.tld : `.${SITE.tld}`;
+        const candidate = parsed.hostname.slice(0, -suffix.length);
+        if (parsed.hostname.endsWith(suffix) && /^[a-z0-9][a-z0-9-]*$/.test(candidate)) serviceId = candidate;
+      } catch (_) { /* invalid redirect is handled by the normal auth flow */ }
+    }
+
     try {
       const res = await secureFetch('/api/v1/totp/verify', {
         method: 'POST',
         headers: { 'Content-Type': 'application/json' },
-        body: JSON.stringify({ code })
+        body: JSON.stringify({ code, serviceId })
       });
       const data = await res.json();
 
@@ -106,7 +117,6 @@
         }
         hideTotpOverlay();
         // Check if redirected here from another service
-        const redirect = safeSessionGet('totp_redirect');
         if (redirect) {
           try { sessionStorage.removeItem('totp_redirect'); } catch (_) {}
           // .sami is an unregistered TLD, so browsers silently drop the