Fix navigation

frontend/src/components/ui/SubNav.tsx

@@ -0,0 +1,27 @@
+interface SubNavProps {
+  tabs: { key: string; label: string }[];
+  activeTab: string;
+  onTabChange: (key: string) => void;
+}
+
+export function SubNav({ tabs, activeTab, onTabChange }: SubNavProps) {
+  return (
+    <div className="max-w-5xl mx-auto w-full px-6 pt-4">
+      <div className="flex gap-2 border-b border-warm-200 dark:border-warm-700">
+        {tabs.map((tab) => (
+          <button
+            key={tab.key}
+            className={`px-4 py-2 text-sm font-medium border-b-2 ${
+              activeTab === tab.key
+                ? 'border-teal-500 text-teal-700 dark:text-teal-400'
+                : 'border-transparent text-warm-500 dark:text-warm-400 hover:text-warm-700 dark:hover:text-warm-300'
+            }`}
+            onClick={() => onTabChange(tab.key)}
+          >
+            {tab.label}
+          </button>
+        ))}
+      </div>
+    </div>
+  );
+}