feat: add continue script functionality for AI-generated audiobook projects

qwen3-tts-frontend/src/locales/en-US/audiobook.json

@@ -114,7 +114,15 @@
       "processAllStarted": "All tasks triggered",
       "parseAllStarted": "Batch extraction started",
       "doneBadge": "{{count}} segments done",
-      "segmentProgress": "{{done}}/{{total}} segments"
+      "segmentProgress": "{{done}}/{{total}} segments",
+      "continueScript": "Continue Script",
+      "continueScriptStarted": "Continue script generation started"
+    },
+    "continueScriptDialog": {
+      "title": "Continue AI Script",
+      "label": "Additional chapters (1-20)",
+      "start": "Start",
+      "starting": "Generating..."
     },
 
     "segments": {

qwen3-tts-frontend/src/locales/ja-JP/audiobook.json

@@ -113,7 +113,15 @@
       "processAllStarted": "すべてのタスクを開始しました",
       "parseAllStarted": "一括抽出を開始しました",
       "doneBadge": "{{count}} セグメント完了",
-      "segmentProgress": "{{done}}/{{total}} セグメント"
+      "segmentProgress": "{{done}}/{{total}} セグメント",
+      "continueScript": "章を続けて生成",
+      "continueScriptStarted": "続き生成を開始しました"
+    },
+    "continueScriptDialog": {
+      "title": "AIスクリプトの続き生成",
+      "label": "追加章数（1-20）",
+      "start": "生成開始",
+      "starting": "生成中..."
     },
 
     "segments": {

qwen3-tts-frontend/src/locales/ko-KR/audiobook.json

@@ -113,7 +113,15 @@
       "processAllStarted": "모든 작업이 시작되었습니다",
       "parseAllStarted": "일괄 추출이 시작되었습니다",
       "doneBadge": "{{count}}개 세그먼트 완료",
-      "segmentProgress": "{{done}}/{{total}} 세그먼트"
+      "segmentProgress": "{{done}}/{{total}} 세그먼트",
+      "continueScript": "챕터 계속 생성",
+      "continueScriptStarted": "이어쓰기 생성이 시작되었습니다"
+    },
+    "continueScriptDialog": {
+      "title": "AI 스크립트 이어쓰기",
+      "label": "추가 챕터 수（1-20）",
+      "start": "생성 시작",
+      "starting": "생성 중..."
     },
 
     "segments": {

qwen3-tts-frontend/src/locales/zh-CN/audiobook.json

@@ -117,7 +117,15 @@
       "processAllStarted": "全部任务已触发",
       "parseAllStarted": "批量提取已开始",
       "doneBadge": "已完成 {{count}} 段",
-      "segmentProgress": "{{done}}/{{total}} 段"
+      "segmentProgress": "{{done}}/{{total}} 段",
+      "continueScript": "续写章节",
+      "continueScriptStarted": "续写任务已开始"
+    },
+    "continueScriptDialog": {
+      "title": "续写 AI 剧本章节",
+      "label": "续写章节数（1-20）",
+      "start": "开始续写",
+      "starting": "生成中..."
     },
 
     "segments": {

qwen3-tts-frontend/src/locales/zh-TW/audiobook.json

@@ -113,7 +113,15 @@
       "processAllStarted": "全部任務已觸發",
       "parseAllStarted": "批量提取已開始",
       "doneBadge": "已完成 {{count}} 段",
-      "segmentProgress": "{{done}}/{{total}} 段"
+      "segmentProgress": "{{done}}/{{total}} 段",
+      "continueScript": "續寫章節",
+      "continueScriptStarted": "續寫任務已開始"
+    },
+    "continueScriptDialog": {
+      "title": "續寫 AI 劇本章節",
+      "label": "續寫章節數（1-20）",
+      "start": "開始續寫",
+      "starting": "生成中..."
     },
 
     "segments": {