feat(video-from-script): 升级可灵视频生成使用官方 API 并添加失败重试机制

- 使用 AK/SK → JWT (HMAC-SHA256) 鉴权替代旧版 API Key
- 支持多种凭证来源：~/.config/kling/.credentials 或 config.json
- 更新 API 端点至官方规范 (v1/videos/image2video)
- 添加 `--retry-failed` 参数支持失败 item 状态重置和重试
- 更新 manifest 文档添加状态机和失败处理说明
- 调整模型名称和参数格式以匹配新 API

.claude/skills/config.json

@@ -17,8 +17,9 @@
   "veoEnhancePrompt": true,
   "veoEnableUpsample": true,
   "kelingApiBaseUrl": "https://api-beijing.klingai.com",
-  "kelingApiKey": "nreeg9bbKekdeenAma4KA3bkHMQkG4ND",
-  "kelingModel": "Kling-V2-5-Turbo",
+  "kelingApiKey": "AR4kMTEGaaM4d4QgJmLYMgHmEFABJPFE",
+  "kelingSecretAccessKey": "aBCrHLYTPPgMm3mnE8RBMAtmY9FLTGT3",
+  "kelingModel": "kling-v2-5-turbo",
   "ossRegion": "oss-cn-hangzhou",
   "ossAccessKeyId": "LTAI5tPV9Ag3csf41GZjaLTA",
   "ossAccessKeySecret": "kDqlGeJTKw6tJtFYiaY8vQTFuVIQDs",