clean: 清理前端debug程式碼，保持生產代碼整潔

🧹 清理內容：
- 移除API接收階段的詳細調試資訊
- 移除詞彙點擊路由的debug輸出
- 移除例句檢查的console.log
- 移除各種JSON.stringify調試

✅ 保留功能：
- 例句顯示區塊（藍色區塊）
- 強化的getWordProperty函數
- 同義詞補充機制
- 所有Portal彈窗功能

🎯 代碼狀態：
- 乾淨的生產代碼，無debug污染
- 功能完整且性能優化
- 準備用於後續問題修正

🤖 Generated with [Claude Code](https://claude.ai/code)

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

frontend/app/generate/page.tsx

@@ -55,17 +55,6 @@ function GenerateContent() {
         console.log('✅ API分析完成:', result)
 
         if (result.success) {
-          console.log('🔍 [DEBUG] 完整API回應:', JSON.stringify(result.data, null, 2));
-          console.log('🔍 [DEBUG] bonus詞彙完整資料:', JSON.stringify(result.data.WordAnalysis?.bonus, null, 2));
-
-          if (result.data.WordAnalysis?.bonus) {
-            console.log('🔍 [DEBUG] bonus例句檢查:');
-            console.log('  - example:', result.data.WordAnalysis.bonus.example);
-            console.log('  - exampleTranslation:', result.data.WordAnalysis.bonus.exampleTranslation);
-            console.log('  - 例句型別:', typeof result.data.WordAnalysis.bonus.example);
-            console.log('  - 例句是否為null:', result.data.WordAnalysis.bonus.example === null);
-          }
-
           setSentenceAnalysis(result.data.WordAnalysis || {})
           setSentenceMeaning(result.data.SentenceMeaning?.Translation || '')
           setGrammarCorrection(result.data.GrammarCorrection || null)

frontend/components/ClickableTextV2.tsx

@@ -177,10 +177,6 @@ export function ClickableTextV2({
     const cleanWord = word.toLowerCase().replace(/[.,!?;:]/g, '')
     const wordAnalysis = analysis?.[cleanWord]
 
-    console.log('🔍 [DEBUG] 點擊詞彙:', cleanWord);
-    console.log('🔍 [DEBUG] analysis物件keys:', Object.keys(analysis || {}));
-    console.log('🔍 [DEBUG] 該詞彙分析:', JSON.stringify(wordAnalysis, null, 2));
-    console.log('🔍 [DEBUG] wordAnalysis存在?:', !!wordAnalysis);
 
     const rect = event.currentTarget.getBoundingClientRect()
     const viewportWidth = window.innerWidth
@@ -219,7 +215,6 @@ export function ClickableTextV2({
     }
 
     if (wordAnalysis) {
-      console.log('✅ [DEBUG] 使用預存分析資料');
       // 場景A：有預存資料的詞彙
       const isHighValue = getWordProperty(wordAnalysis, 'isHighValue')
       if (isHighValue) {
@@ -234,9 +229,6 @@ export function ClickableTextV2({
         onWordClick?.(cleanWord, wordAnalysis)
       }
     } else {
-      console.log('❌ [DEBUG] 詞彙不在analysis中，調用queryWordWithAI');
-      console.log('🔍 [DEBUG] 要查找的詞彙:', cleanWord);
-      console.log('🔍 [DEBUG] analysis中的詞彙:', Object.keys(analysis || {}));
       // 場景B：無預存資料的詞彙 → 即時調用 AI 查詢
       await queryWordWithAI(cleanWord, position)
     }
@@ -470,9 +462,7 @@ export function ClickableTextV2({
             {/* 例句區塊 - 藍色 */}
             {(() => {
               const example = getWordProperty(analysis[selectedWord], 'example');
-              const exampleTranslation = getWordProperty(analysis[selectedWord], 'exampleTranslation');
-              console.log('🔍 [DEBUG] 例句檢查:', {example, exampleTranslation});
-              return example && example !== 'null';
+              return example && example !== 'null' && example !== 'undefined';
             })() && (
               <div className="bg-blue-50 rounded-lg p-3 border border-blue-200">
                 <h4 className="font-semibold text-blue-900 mb-2 text-left text-sm">例句</h4>