Fix JSX ReferenceError: escape {{wordId}} literal in option text

{{wordId}} in JSX is parsed as a JS expression trying to resolve the variable
`wordId`. Wrap in a string expression so it renders as literal text.

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

src/pages/ContentCreation.jsx

@@ -411,7 +411,7 @@ function PairForm({ objectId, allObjects, onPairSaved }) {
                         {matchingObjs.length > 0 ? (
                           <select value={assigned} onChange={e => setObjectAssignments(prev => ({ ...prev, [w.id]: e.target.value || null }))}
                             className={`flex-1 text-xs border rounded px-1.5 py-0.5 bg-white focus:outline-none focus:ring-1 focus:ring-indigo-400 ${assigned ? 'border-indigo-400 text-indigo-700 bg-indigo-50' : 'border-slate-200 text-slate-500'}`}>
-                            <option value="">— nur Wort ({{wordId}})</option>
+                            <option value="">{'— nur Wort ({{wordId}})'}</option>
                             {matchingObjs.map(obj => {
                               const idx = safeObjects.indexOf(obj);
                               const labels = (obj._words || []).slice(0, 3).map(ow => ow.titel_de || ow.id).join(', ');