fix(admin): prevent infinite reload loop on 401

app/templates/dashboard.html

@@ -393,7 +393,18 @@
     // ── API Helpers ─────────────────────────────────────────────
     async function api(path, opts = {}) {
         const r = await fetch(path, { ...opts, headers: { 'Authorization': 'Bearer ' + masterKey, 'Content-Type': 'application/json', ...(opts.headers || {}) } });
-        if (r.status === 401) { sessionStorage.removeItem('apiarium_master_key'); location.reload(); return null; }
+        if (r.status === 401) {
+            console.error('Auth failed for', path, await r.text());
+            if (path === '/admin/keys') {
+                sessionStorage.removeItem('apiarium_master_key');
+                showAuth();
+                authError.textContent = 'Invalid master key';
+                authError.classList.remove('hidden');
+            } else {
+                console.warn('Endpoint returned 401:', path);
+            }
+            return null;
+        }
         return r;
     }