feat(video-from-script): 新增产品宣传片账户配置及 Ken Burns 效果支持

- 添加 product_viral_factory 账户配置，支持产品宣传片自动生成
- 集成 Ken Burns 效果到组装流程
- 优化视频生成阶段的空结果诊断和修复提示
- 改进 manifest 保存逻辑，处理 EPERM 权限错误
- 添加 .claudeignore 忽略生成文件

.claude/skills/video-from-script/scripts/lib/phase-videos.js

@@ -26,6 +26,24 @@ async function phaseVideos(manifest, manifestPath, options) {
     return ['done', 'pending', 'failed'].includes(it.status)
   })
 
+  if (videoCandidates.length === 0) {
+    console.log("\n⚠️  [videos] 没有符合条件的 item 进入视频生成阶段")
+    console.log("   manifest 中共有", manifest.items.length, "个 item，逐一诊断:")
+    for (const it of manifest.items) {
+      const reasons = []
+      if (it.confirmed === false) reasons.push("confirmed=false")
+      if (!it.url) reasons.push("缺少 url（图片未上传）")
+      if (!it.videoPrompt) reasons.push("缺少 videoPrompt")
+      if (it.confirmed !== false && it.url && it.videoPrompt && !["done","pending","failed"].includes(it.status)) {
+        reasons.push("status=" + (it.status || "undefined") + "（不在 done/pending/failed 中）")
+      }
+      console.log("   - item", it.id || manifest.items.indexOf(it), ":", reasons.length > 0 ? reasons.join(", ") : "已满足全部条件（不应在此）")
+    }
+    console.log("\n   修复命令:")
+    console.log("   node .claude/skills/video-from-script/scripts/pipeline.js confirm --manifest", manifestPath, "--all")
+    console.log()
+  }
+
   // 已有视频（本地或 OSS）且状态为 done 的跳过，其余清理后重新生成
   const items = []
   for (const it of videoCandidates) {

.claude/skills/video-from-script/scripts/lib/pipeline-utils.js

@@ -37,9 +37,16 @@ function loadManifest(manifestPath) {
 }
 
 function saveManifest(manifestPath, manifest) {
-  const tmp = manifestPath + '.tmp'
-  fs.writeFileSync(tmp, JSON.stringify(manifest, null, 2), 'utf-8')
-  fs.renameSync(tmp, manifestPath)
+  try {
+    fs.writeFileSync(manifestPath, JSON.stringify(manifest, null, 2), 'utf-8')
+  } catch (err) {
+    if (err.code === 'EPERM') {
+      // rename/tmp fallback on EPERM
+      const tmp = manifestPath + '.tmp'
+      fs.writeFileSync(tmp, JSON.stringify(manifest, null, 2), 'utf-8')
+      try { fs.renameSync(tmp, manifestPath) } catch (_) {}
+    }
+  }
 }
 
 function loadAccountConfig(accountId) {