feat: support DUFS webdav

[wfion]

修改点：

• 根因是 DUFS 同时返回 Digest 和 Basic 两条 WWW-Authenticate，webdav_client 1.2.2 使用单值接口读取时直接抛异常。
• 在响应拦截器中合并多条认证挑战，使依赖能够继续进行 Digest 认证。
• 新增回归测试，覆盖双认证头、连接检测、创建目录、上传及恢复流程。
• 实际服务器已验证 Digest、MKCOL、PUT、GET、DELETE 均正常。

根据 @xream 提供的公网服务 测试日志文件如下， 无法进行上传

Log(logLevel: LogLevel.info, payload: [APP] WebDAV ping successful, dateTime: 2026-07-27 21:35:04)
Log(logLevel: LogLevel.info, payload: [APP] updateGroups error: getProxiesGroups returned empty after inner retries, dateTime: 2026-07-27 21:35:14)
Log(logLevel: LogLevel.info, payload: [APP] WebDAV ping successful, dateTime: 2026-07-27 21:35:22)
Log(logLevel: LogLevel.info, payload: [APP] updateGroups error: getProxiesGroups returned empty after inner retries, dateTime: 2026-07-27 21:35:22)
Log(logLevel: LogLevel.info, payload: [APP] Starting backup: 0 profiles, current: null, dateTime: 2026-07-27 21:35:24)
Log(logLevel: LogLevel.info, payload: [APP] WebDAV backup: uploading 2731 bytes to /Bettbox/backup.zip, dateTime: 2026-07-27 21:35:24)
Log(logLevel: LogLevel.info, payload: [APP] WebDAV mkdir warning (may already exist): Exception: "www-authenticate" header has more than one value, please use Headers[name], dateTime: 2026-07-27 21:35:24)
Log(logLevel: LogLevel.info, payload: [APP] WebDAV backup attempt 1 failed: Exception: "www-authenticate" header has more than one value, please use Headers[name], retrying in 2s..., dateTime: 2026-07-27 21:35:24)
Log(logLevel: LogLevel.info, payload: [APP] WebDAV backup: uploading 2731 bytes to /Bettbox/backup.zip, dateTime: 2026-07-27 21:35:26)
Log(logLevel: LogLevel.info, payload: [APP] WebDAV mkdir warning (may already exist): Exception: "www-authenticate" header has more than one value, please use Headers[name], dateTime: 2026-07-27 21:35:27)
Log(logLevel: LogLevel.info, payload: [APP] WebDAV backup attempt 2 failed: Exception: "www-authenticate" header has more than one value, please use Headers[name], retrying in 4s..., dateTime: 2026-07-27 21:35:27)
Log(logLevel: LogLevel.info, payload: [APP] WebDAV backup: uploading 2731 bytes to /Bettbox/backup.zip, dateTime: 2026-07-27 21:35:31)
Log(logLevel: LogLevel.info, payload: [APP] WebDAV mkdir warning (may already exist): Exception: "www-authenticate" header has more than one value, please use Headers[name], dateTime: 2026-07-27 21:35:32)
Log(logLevel: LogLevel.info, payload: [APP] WebDAV backup failed after 3 attempts: Exception: "www-authenticate" header has more than one value, please use Headers[name], dateTime: 2026-07-27 21:35:32)
Log(logLevel: LogLevel.info, payload: [APP] WebDAV backup failed: Exception: "www-authenticate" header has more than one value, please use Headers[name], dateTime: 2026-07-27 21:35:32)
Log(logLevel: LogLevel.info, payload: [APP] updateGroups error: getProxiesGroups returned empty after inner retries, dateTime: 2026-07-27 21:35:47)
Log(logLevel: LogLevel.info, payload: [APP] updateGroups error: getProxiesGroups returned empty after inner retries, dateTime: 2026-07-27 21:36:13)
Log(logLevel: LogLevel.info, payload: [APP] updateGroups error: getProxiesGroups returned empty after inner retries, dateTime: 2026-07-27 21:36:43)
Log(logLevel: LogLevel.info, payload: [APP] updateGroups error: getProxiesGroups returned empty after inner retries, dateTime: 2026-07-27 21:39:38)

[appshubcc]

@wfion 思路是对的，按理说这个逻辑也不复杂，具体你们测试通了就行，我没这个场景就不试了。。

[appshubcc]

试了下，合了

[wfion]

试了下，合了

好的 我去试试pre版本

[wfion]

试了下，合了

好的 我去试试pre版本

[appshubcc]

@wfion 下个pre~

[wfion]

试了下，合了

@appshubcc pre12版本 测试x86安卓 好像代码没在里面

[appshubcc]

@wfion 正在编译

[xream]

DUFS 能用了

[wfion]

@appshubcc 这个pr也可以了，两个应该都行了~