feat(video-pipeline): 添加关键字氛围词花字叠加和Oss URL回写功能

- 新增 Q17 关键字氛围词问答项，支持关闭/默认/自定义花字效果
- 在 manifest 和 account.json 中添加 keyword 和 keywordStyle 字段
- 实现关键字氛围词在画面中央的叠加逻辑，支持动画、阴影、文字效果等配置
- 在 assemble 流程中增加 `keywords` 步骤，自动读取账号配置生成花字
- 修复音频上传后未回写 OSS URL 到 manifest 的问题，避免重复上传

.claude/skills/video-from-script/scripts/capcut_assemble.js

@@ -288,7 +288,7 @@ async function assemble(args) {
 
   const steps = []
   if (mode === 'images') steps.push('upload')
-  steps.push('draft', 'materials', 'audio_oss', 'voiceover', 'audio', 'subtitles', 'effects', 'filter', 'save', 'sync')
+  steps.push('draft', 'materials', 'audio_oss', 'voiceover', 'audio', 'subtitles', 'keywords', 'effects', 'filter', 'save', 'sync')
   const totalSteps = steps.length
   let step = 0
 
@@ -380,6 +380,25 @@ async function assemble(args) {
     try {
       audioUrls = await batchUploadAudio(inputDir, items)
       console.log(`   成功: ${Object.keys(audioUrls).length} 段音频\n`)
+      // 回写 OSS URL 到 manifest，避免重复上传
+      if (Object.keys(audioUrls).length > 0 && manifestFile) {
+        let changed = false
+        for (const item of manifest.items) {
+          if (item.audio && audioUrls[item.audio]) {
+            item.audio = audioUrls[item.audio]
+            changed = true
+          }
+          if (item.segments) {
+            for (const seg of item.segments) {
+              if (seg.audio && audioUrls[seg.audio]) {
+                seg.audio = audioUrls[seg.audio]
+                changed = true
+              }
+            }
+          }
+        }
+        if (changed) saveManifest(manifestFile, manifest)
+      }
     } catch (err) {
       console.log(`   OSS 上传失败，将尝试本地路径: ${err.message}\n`)
     }
@@ -415,6 +434,15 @@ async function assemble(args) {
     console.log('   跳过')
   }
 
+  // -- 添加关键字氛围词 --
+  step++; console.log(`[${step}/${totalSteps}] 添加关键字氛围词...`)
+  const keywordStyle = loadKeywordStyle(manifest)
+  if (Object.keys(keywordStyle).length > 0 && items.some(i => i.keyword)) {
+    await addKeywordOverlays(draftUrl, items, timeline, keywordStyle)
+  } else {
+    console.log('   跳过（无关键字或未配置 keywordStyle）')
+  }
+
   // -- 添加特效 --
   step++; console.log(`[${step}/${totalSteps}] 添加特效...`)
   if (effectsStr) {
@@ -796,6 +824,75 @@ function loadSubtitleStyle(manifest) {
   } catch { return {} }
 }
 
+function loadKeywordStyle(manifest) {
+  const account = manifest.account
+  if (!account) return {}
+  const scriptDir = __dirname
+  const accountFile = path.join(scriptDir, '..', '..', '..', 'accounts', account, 'account.json')
+  if (!fs.existsSync(accountFile)) return {}
+  try {
+    const accountData = JSON.parse(fs.readFileSync(accountFile, 'utf-8'))
+    return accountData.capcut?.keywordStyle || {}
+  } catch { return {} }
+}
+
+// ============================================================================
+// 添加关键字氛围词叠加（画面中央大字）
+// ============================================================================
+
+async function addKeywordOverlays(draftUrl, items, timeline, style = {}) {
+  const keywordItems = items.filter(item => item.keyword)
+  if (keywordItems.length === 0) {
+    console.log('   无关键字，跳过')
+    return
+  }
+
+  const captions = []
+  for (let i = 0; i < items.length; i++) {
+    const item = items[i]
+    if (!item.keyword) continue
+    const tl = timeline[i]
+
+    const cap = {
+      start: tl.start,
+      end: tl.end,
+      text: item.keyword,
+    }
+    if (style.inAnimation) cap.in_animation = style.inAnimation
+    if (style.outAnimation) cap.out_animation = style.outAnimation
+    if (style.inAnimDuration) cap.in_animation_duration = style.inAnimDuration
+    if (style.outAnimDuration) cap.out_animation_duration = style.outAnimDuration
+
+    captions.push(cap)
+  }
+
+  if (captions.length === 0) return
+
+  await api('add_captions', {
+    draft_url: draftUrl,
+    captions: JSON.stringify(captions),
+    font: style.font || null,
+    font_size: style.fontSize || 60,
+    text_color: style.color || '#FFFFFF',
+    alignment: 1,
+    bold: style.bold || false,
+    has_shadow: style.hasShadow || false,
+    shadow_info: style.shadowAlpha ? {
+      shadow_alpha: style.shadowAlpha,
+      shadow_color: style.shadowColor || '#000000',
+      shadow_diffuse: 15,
+      shadow_distance: 5,
+      shadow_angle: -45,
+    } : undefined,
+    alpha: style.alpha || 1,
+    scale_x: 1, scale_y: 1,
+    transform_x: 0,
+    transform_y: style.transformY || 0,
+    text_effect: style.textEffect || null,
+  })
+  console.log(`   已添加 ${captions.length} 个关键字氛围词 (效果: ${style.textEffect || '无'})`)
+}
+
 function loadTransitions(manifest) {
   const account = manifest.account
   if (!account) return null

.claude/skills/video-from-script/scripts/lib/cmd-init.js

@@ -79,6 +79,7 @@ function initManifest(options) {
     }
     if (raw.directorRef) item.directorRef = raw.directorRef
     if (raw.videoPrompt) item.videoPrompt = raw.videoPrompt
+    if (raw.keyword) item.keyword = raw.keyword
     if (resolvedMode === 'framePair') item.lastFramePrompt = raw.lastFramePrompt
     return item
   })