feat: add word-type pairs + difficulty_level to auto create

- Claude now generates 40 pairs: +10 × word type (positive_words / negative_words)
- difficulty easy→1, medium→2 stored as difficulty_level on each pair
- findOrCreateWord() looks up or creates words by title before linking
- savePairsForObject handles all 4 pair types (text/yes_no/question/word)

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

src/pages/ContentCreation.jsx

@@ -890,9 +890,21 @@ async function callClaudeForPairs(picture, allObjects, selectedObjectId) {
   return res.pairs;
 }
 
+async function findOrCreateWord(title, lang) {
+  try {
+    const results = await apiFetch(`/words?search=${encodeURIComponent(title.trim())}&limit=5`);
+    const exact = Array.isArray(results)
+      ? results.find(w => (w[`titel_${lang}`] || w.titel_de || '').toLowerCase() === title.trim().toLowerCase())
+      : null;
+    if (exact) return exact;
+    return await apiPost('/words', { [`titel_${lang}`]: title.trim() });
+  } catch { return null; }
+}
+
 async function savePairsForObject(pairs, objectId, lang, onPairSaved, onProgress) {
   for (let i = 0; i < pairs.length; i++) {
     const p = pairs[i];
+    const difficultyLevel = p.difficulty === 'easy' ? 1 : p.difficulty === 'medium' ? 2 : null;
 
     let questionId = null;
     if (p.type !== 'text' && p.question?.trim()) {
@@ -901,22 +913,41 @@ async function savePairsForObject(pairs, objectId, lang, onPairSaved, onProgress
     }
 
     let posStmtId = null;
-    if ((p.type === 'text' || p.type === 'question') && p.positive?.trim()) {
+    let negStmtId = null;
+
+    if (p.type === 'text' && p.positive?.trim()) {
       const s = await apiPost('/statements', { status: 'draft', [`positive_sentence_${lang}`]: p.positive.trim() });
       posStmtId = s.id;
     } else if (p.type === 'yes_no') {
       const s = await apiPost('/statements', { status: 'draft', answer: p.answer ?? null });
       posStmtId = s.id;
+    } else if (p.type === 'question') {
+      if (p.positive?.trim()) {
+        const s = await apiPost('/statements', { status: 'draft', [`positive_sentence_${lang}`]: p.positive.trim() });
+        posStmtId = s.id;
       }
-
+      if (p.negative?.trim()) {
-    let negStmtId = null;
-    if (p.type === 'question' && p.negative?.trim()) {
         const s = await apiPost('/statements', { status: 'draft', [`negative_sentence_${lang}`]: p.negative.trim() });
         negStmtId = s.id;
       }
+    } else if (p.type === 'word') {
+      if (p.positive_words?.length) {
+        const s = await apiPost('/statements', { status: 'draft' });
+        posStmtId = s.id;
+        const words = await Promise.all(p.positive_words.map(w => findOrCreateWord(w, lang)));
+        await Promise.all(words.filter(Boolean).map(w => apiLink(`/statements/${posStmtId}/positive-words/${w.id}`)));
+      }
+      if (p.negative_words?.length) {
+        const s = await apiPost('/statements', { status: 'draft' });
+        negStmtId = s.id;
+        const words = await Promise.all(p.negative_words.map(w => findOrCreateWord(w, lang)));
+        await Promise.all(words.filter(Boolean).map(w => apiLink(`/statements/${negStmtId}/negative-words/${w.id}`)));
+      }
+    }
 
     const created = await apiPost('/pairs', {
       answer_type: p.type,
+      difficulty_level: difficultyLevel,
       question_id: questionId,
       positive_statement_id: posStmtId,
       negative_statement_id: negStmtId,