feat: API-Key Health-Check für Anthropic-Keys

- POST /api/admin/api-keys/{keyId}/check Endpoint
- Sendet minimale Anfrage an Anthropic API, liest Rate-Limit-Headers
- Plan-Erkennung: Max (Overage > 0), Pro (kein Fallback-Header), Pro/Max (sonst), API Console
- Budget-Auslastung: 5h + 7d + Overage mit Status-Warnings
- Frontend: Heartbeat-Button zeigt Ergebnis inline unter dem Key-Eintrag
- apiCheckApiKey() API-Funktion

wwwroot/js/api.js

@@ -645,6 +645,15 @@ async function apiDeleteApiKey(keyId) {
   return resp.json();
 }
 
+async function apiCheckApiKey(keyId) {
+  const resp = await fetch('/api/admin/api-keys/' + keyId + '/check', { method: 'POST' });
+  if (!resp.ok) {
+    const err = await resp.json().catch(() => ({}));
+    throw new Error(err.error || 'Fehler beim Prüfen');
+  }
+  return resp.json();
+}
+
 // ── Krea Image API ──
 
 async function apiKreaStatus() {

wwwroot/js/pages/api-keys-page.js

@@ -32,6 +32,8 @@ registerPage('api-keys', {
       }
 
       keys.forEach(function(key) {
+        var wrapper = document.createElement('div');
+
         var row = document.createElement('div');
         row.className = 'admin-user-row';
 
@@ -54,6 +56,21 @@ registerPage('api-keys', {
         var actions = document.createElement('div');
         actions.className = 'admin-user-actions';
 
+        // Status-Zeile (für Check-Ergebnis)
+        var statusLine = document.createElement('div');
+        statusLine.className = 'admin-user-meta';
+        statusLine.style.cssText = 'padding:0 var(--box-padding) .5rem;display:none;font-size:.85em';
+
+        // Check (nur Anthropic)
+        if (key.provider === 'anthropic') {
+          var checkBtn = document.createElement('button');
+          checkBtn.className = 'icon-btn';
+          checkBtn.title = 'Key prüfen';
+          checkBtn.innerHTML = '<i class="fa fa-heartbeat"></i>';
+          checkBtn.addEventListener('click', function() { checkKey(key, checkBtn, statusLine); });
+          actions.appendChild(checkBtn);
+        }
+
         // Bearbeiten
         var editBtn = document.createElement('button');
         editBtn.className = 'icon-btn';
@@ -89,7 +106,9 @@ registerPage('api-keys', {
 
         row.appendChild(info);
         row.appendChild(actions);
-        list.appendChild(row);
+        wrapper.appendChild(row);
+        wrapper.appendChild(statusLine);
+        list.appendChild(wrapper);
       });
     }
 
@@ -102,6 +121,39 @@ registerPage('api-keys', {
       }
     }
 
+    async function checkKey(key, btn, statusLine) {
+      var origHtml = btn.innerHTML;
+      btn.innerHTML = '<i class="fa fa-spinner fa-spin"></i>';
+      btn.disabled = true;
+      statusLine.style.display = 'block';
+      statusLine.textContent = 'Prüfe…';
+      statusLine.style.opacity = '0.5';
+      try {
+        var result = await apiCheckApiKey(key.keyId);
+        statusLine.style.opacity = '1';
+        if (result.status === 'ok') {
+          var parts = ['✅ Gültig', result.keyType];
+          if (result.usage5h != null) parts.push('5h: ' + result.usage5h + '%');
+          if (result.usage7d != null) {
+            var s7d = '7d: ' + result.usage7d + '%';
+            if (result.status7d === 'allowed_warning') s7d += ' ⚠️';
+            else if (result.status7d === 'exceeded') s7d += ' 🛑';
+            parts.push(s7d);
+          }
+          if (result.overage != null && result.overage > 0) parts.push('Overage: ' + result.overage + '%');
+          statusLine.textContent = parts.join(' · ');
+        } else {
+          statusLine.textContent = '❌ ' + (result.message || 'Unbekannter Fehler');
+        }
+      } catch (err) {
+        statusLine.style.opacity = '1';
+        statusLine.textContent = '❌ ' + err.message;
+      } finally {
+        btn.innerHTML = origHtml;
+        btn.disabled = false;
+      }
+    }
+
     function startEdit(key) {
       editingKeyId = key.keyId;
       formTitle.textContent = 'API-Key bearbeiten';