Fix: Replace extra </div> with </> for fragment closing

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

studio-v2/app/learn/[unitId]/flashcards/page.tsx

@@ -181,6 +181,6 @@ export default function FlashcardsPage() {
           </div>
         )}
       </div>
-    </div>
+    </>
   )
 }

studio-v2/app/learn/[unitId]/listen/page.tsx

@@ -132,6 +132,6 @@ export default function ListenPage() {
           </div>
         ) : null}
       </div>
-    </div>
+    </>
   )
 }

studio-v2/app/learn/[unitId]/match/page.tsx

@@ -165,6 +165,6 @@ export default function MatchPage() {
           </div>
         )}
       </div>
-    </div>
+    </>
   )
 }

studio-v2/app/learn/[unitId]/pronounce/page.tsx

@@ -128,6 +128,6 @@ export default function PronouncePage() {
           </div>
         ) : null}
       </div>
-    </div>
+    </>
   )
 }

studio-v2/app/learn/[unitId]/quiz/page.tsx

@@ -152,6 +152,6 @@ export default function QuizPage() {
           <p className={isDark ? 'text-white/60' : 'text-slate-500'}>Keine Quiz-Fragen verfuegbar.</p>
         )}
       </div>
-    </div>
+    </>
   )
 }

studio-v2/app/learn/[unitId]/story/page.tsx

@@ -169,6 +169,6 @@ export default function StoryPage() {
           )}
         </div>
       </div>
-    </div>
+    </>
   )
 }

studio-v2/app/learn/[unitId]/type/page.tsx

@@ -186,6 +186,6 @@ export default function TypePage() {
           <p className={isDark ? 'text-white/60' : 'text-slate-500'}>Keine Vokabeln verfuegbar.</p>
         )}
       </div>
-    </div>
+    </>
   )
 }