refactor(alias): return URL when root has .proxy suffix

[j2rong4cn]

根目录以.proxy结尾时返回代理链接
可以让crypt、mega等驱动(不返回URL的) 更好的支持并发
路径设置示例：
crypt.proxy:/crypt
mega.proxy:/mega

[Copilot]

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

Comments suppressed due to low confidence (2)

drivers/alias/util.go:120

• [nitpick] Consider adding an inline comment explaining that using common.NoProxyRangeMark (-1) for Concurrency acts as a flag to disable proxy range handling.

Concurrency: common.NoProxyRangeMark,

drivers/alias/driver.go:112

• [nitpick] Consider adding a comment explaining that the .proxy suffix forces args.Redirect to true to support concurrent downloads in proxy mode.

if strings.HasSuffix(root, ".proxy") {