i18n: Translate all Chinese to English across the codebase

Translate Chinese comments, log/error messages, validator labels and
Swagger annotations to English throughout the source code, generated
Swagger docs, config files and CI workflows.

Make the English README primary: README.md now holds the English docs
and README_EN.md holds the Chinese version, with cross-language links
updated accordingly.

Note: the generated docs/ swagger files were translated in place; run
`go generate ./...` (swag init) to regenerate them from the now-English
annotations when a Go toolchain is available.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

http/controller/admin/rustdesk.go

@@ -25,7 +25,7 @@ func (r *Rustdesk) CmdList(c *gin.Context) {
 		return
 	}
 	res := service.AllService.ServerCmdService.List(q.Page, 9999)
-	//在列表前添加系统命令
+	//add system commands before the list
 	list := make([]*model.ServerCmd, 0)
 	list = append(list, model.SysIdServerCmds...)
 	list = append(list, model.SysRelayServerCmds...)