Add AI Enhance toggle for better genre accuracy

When enabled, uses the LLM to enrich genre/style tags into detailed
music descriptions and generate proper BPM, key, and time signature
metadata (CoT features). Fixes genre tags like "pop, rock" producing
ballad-like output by matching Gradio UI default behavior.

- Add enhance toggle in Style of Music card header
- Gate CoT metas/caption/language by enhance OR thinking flag
- Remove unsupported --lm-backend/--lm-model from Python fallback
- Add i18n translations (en/zh/ja/ko) with tooltip

i18n/translations.ts

@@ -265,6 +265,9 @@ export const translations = {
     randomSeedRecommended: 'Randomized every run (recommended)',
     fixedSeedReproducible: 'Fixed seed for reproducible results',
     enterFixedSeed: 'Enter fixed seed',
+    enhance: 'AI Enhance',
+    enhanceHint: 'better genre accuracy, slightly slower',
+    enhanceTooltip: 'Uses the AI language model to enrich your genre/style tags into a detailed music description and generate proper BPM, key, and time signature. Improves genre accuracy but adds 10-20s to generation time. No extra VRAM needed.',
     thinkingCot: 'Thinking (CoT)',
     mp3Smaller: 'MP3 (smaller)',
     flacLossless: 'FLAC (lossless)',
@@ -861,6 +864,9 @@ export const translations = {
     randomSeedRecommended: '每次运行随机（推荐）',
     fixedSeedReproducible: '固定种子以获得可重现结果',
     enterFixedSeed: '输入固定种子',
+    enhance: 'AI 增强',
+    enhanceHint: '更准确的风格，稍慢',
+    enhanceTooltip: '使用AI语言模型将风格标签丰富为详细的音乐描述，并生成准确的BPM、调性和拍号。提高风格准确度，但增加10-20秒生成时间。无需额外显存。',
     thinkingCot: '思考模式（CoT）',
     mp3Smaller: 'MP3（较小）',
     flacLossless: 'FLAC（无损）',
@@ -1457,6 +1463,9 @@ export const translations = {
     randomSeedRecommended: '毎回ランダム化（推奨）',
     fixedSeedReproducible: '再現可能な結果のための固定シード',
     enterFixedSeed: '固定シードを入力',
+    enhance: 'AI エンハンス',
+    enhanceHint: 'ジャンル精度向上、やや遅い',
+    enhanceTooltip: 'AIがジャンル/スタイルタグを詳細な音楽説明に変換し、適切なBPM、キー、拍子を生成します。ジャンルの精度が向上しますが、生成に10-20秒追加されます。追加VRAMは不要です。',
     thinkingCot: '思考（CoT）',
     mp3Smaller: 'MP3（小さい）',
     flacLossless: 'FLAC（ロスレス）',
@@ -2053,6 +2062,9 @@ export const translations = {
     randomSeedRecommended: '매 실행마다 무작위 (권장)',
     fixedSeedReproducible: '재현 가능한 결과를 위한 고정 시드',
     enterFixedSeed: '고정 시드 입력',
+    enhance: 'AI 향상',
+    enhanceHint: '더 정확한 장르, 약간 느림',
+    enhanceTooltip: 'AI 언어 모델을 사용하여 장르/스타일 태그를 상세한 음악 설명으로 변환하고 적절한 BPM, 키, 박자를 생성합니다. 장르 정확도가 향상되지만 생성 시간이 10-20초 추가됩니다. 추가 VRAM이 필요하지 않습니다.',
     thinkingCot: '생각 (CoT)',
     mp3Smaller: 'MP3 (작음)',
     flacLossless: 'FLAC (무손실)',