feat: unified ContentCreation tool (Object + Statement creation merged)

- New ContentCreation.jsx: 3-column layout
  Left: object list + "＋ Objekt hinzufügen" button
  Center: dual-mode canvas (draw OR highlight)
  Right: ObjectAddPanel (mode=add) or PairsPanel (mode=objectId)
- After saving object → auto-switches to PairsPanel for that object
- All ObjectCreation + StatementCreation logic merged into one page
- All pictures loaded (no objects_created filter)
- "Objekte abgeschlossen" button marks picture (visual badge)
- ContentHub: 2 tiles (Content Erstellen + Veröffentlichen placeholder)
- App.jsx: /content/creation route, old /content/objects + /content/statements removed

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/App.jsx

@@ -5,8 +5,7 @@ import Dashboard from './pages/Dashboard';
 import DatabaseAdmin from './pages/DatabaseAdmin';
 import TableView from './pages/TableView';
 import ContentHub from './pages/ContentHub';
-import ObjectCreation from './pages/ObjectCreation';
+import ContentCreation from './pages/ContentCreation';
-import StatementCreation from './pages/StatementCreation';
 
 function RequireAuth({ children }) {
   const user = getUser();
@@ -23,8 +22,7 @@ export default function App() {
         <Route path="/db" element={<RequireAuth><DatabaseAdmin /></RequireAuth>} />
         <Route path="/db/:tableKey" element={<RequireAuth><TableView /></RequireAuth>} />
         <Route path="/content" element={<RequireAuth><ContentHub /></RequireAuth>} />
-        <Route path="/content/objects" element={<RequireAuth><ObjectCreation /></RequireAuth>} />
+        <Route path="/content/creation" element={<RequireAuth><ContentCreation /></RequireAuth>} />
-        <Route path="/content/statements" element={<RequireAuth><StatementCreation /></RequireAuth>} />
         <Route path="*" element={<Navigate to="/" replace />} />
       </Routes>
     </BrowserRouter>

src/pages/ContentHub.jsx

@@ -3,27 +3,19 @@ import Layout from '../components/Layout';
 
 const TOOLS = [
   {
-    key: 'objects',
+    key: 'creation',
-    title: 'Object Creation',
+    title: 'Content Erstellen',
-    icon: '🖼️',
+    icon: '🎨',
-    description: 'Bilder durchblättern, Bereiche einzeichnen und Objekte mit Wörtern verknüpfen.',
+    description: 'Objekte in Bildern einzeichnen, Wörter verknüpfen und Pairs mit Fragen & Aussagen erstellen.',
-    path: '/content/objects',
-    ready: true,
-  },
-  {
-    key: 'statements',
-    title: 'Statement Creation',
-    icon: '💬',
-    description: 'Pairs mit Fragen und Aussagen erstellen, Wörter im Satz markieren.',
-    path: '/content/statements',
-    ready: true,
-  },
-  {
-    key: 'content',
-    title: 'Content Creation',
-    icon: '✨',
-    description: 'Inhalte zusammenstellen und veröffentlichen.',
     path: '/content/creation',
+    ready: true,
+  },
+  {
+    key: 'publish',
+    title: 'Veröffentlichen',
+    icon: '✨',
+    description: 'Fertige Pairs prüfen, freigeben und veröffentlichen.',
+    path: '/content/publish',
     ready: false,
   },
 ];
@@ -36,7 +28,7 @@ export default function ContentHub() {
       <div className="max-w-3xl mx-auto">
         <h1 className="text-2xl font-bold text-slate-800 mb-2">Content Verwaltung</h1>
         <p className="text-slate-500 mb-8">Wähle ein Tool um loszulegen.</p>
-        <div className="grid grid-cols-1 sm:grid-cols-3 gap-5">
+        <div className="grid grid-cols-1 sm:grid-cols-2 gap-5">
           {TOOLS.map(tool => (
             <button
               key={tool.key}