feat(driver): add CtFile OpenAPI driver

[SenkjM]

Summary / 摘要

Add CtFile (城通网盘) storage driver using only the official OpenAPI (https://rest.ctfile.com/v1). Auth is the OpenAPI session token from「开放接口登录密钥管理」; client-login / crack flows are out of scope.

User-visible

• New storage type CtFile: list / download / upload / mkdir / rename / move / copy / remove.
• Configure with OpenAPI session token (secret); optional cloud_type (public/private), base_url, sort, and User-Agent.

Implementation

• New package drivers/ctfile, registered in drivers/all.go.

• Folder vs file by key prefix (d… / f…); list merges folder + file APIs and dedupes.

• Upload uses size+md5; large uploads go through stream.CacheFullAndHash.

• This PR has breaking changes.
  / 此 PR 包含破坏性变更。

• This PR changes public API, config, storage format, or migration behavior.
  / 此 PR 修改了公开 API、配置、存储格式或迁移行为。

• This PR requires corresponding changes in related repositories.
  / 此 PR 需要关联仓库同步修改。

Related repository PRs / 关联仓库 PR:

• OpenList-Frontend: SenkjM/OpenList-Frontend feat/ctfile-driver (drivers.json i18n)
• OpenList-Docs: (optional)

Testing / 测试

• go test ./drivers/ctfile/...
• go test ./...
• Manual test / 手动测试:
  • Add CtFile storage with OpenAPI session
  • List root / nested folders
  • Download
  • Upload small file
  • Mkdir / rename / move / copy / delete

Checklist / 检查清单

• I have read CONTRIBUTING.
  / 我已阅读 CONTRIBUTING。
• I confirm this contribution follows the repository license, contribution policy, and code of conduct.
  / 我确认此贡献符合仓库许可证、贡献规范和行为准则。
• I have formatted the changed code with gofmt, go fmt, or prettier where applicable.
  / 我已按适用情况使用 gofmt、go fmt 或 prettier 格式化变更代码。
• I have requested review from relevant maintainers or code owners where applicable.
  / 我已在适用情况下请求相关维护者或代码所有者审查。

AI Disclosure / AI 使用声明

• This PR includes AI-assisted content.
  / 此 PR 包含 AI 辅助内容。

Tools used / 使用工具:

• ChatGPT
• Codex
• GitHub Copilot
• Claude
• Gemini
• Other (please specify) / 其他（请注明）: Grok Bot

Usage scope / 使用范围:

• Code generation / 代码生成

• Refactoring / 重构

• Documentation / 文档

• Tests / 测试

• Translation / 翻译

• Review assistance / 审查辅助

• I have reviewed and validated all AI-assisted content included in this PR.
  / 我已审核并验证此 PR 中的所有 AI 辅助内容。

• I have ensured that all AI-assisted commits include Co-Authored-By attribution.
  / 我已确保所有 AI 辅助提交都包含 Co-Authored-By 归属信息。

• I can reproduce all AI-assisted content included in this PR without any AI tools.
  / 我可以在没有任何 AI 工具的情况下重现此 PR 中包含的所有 AI 辅助内容。