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/middleware/admin.go

@@ -6,11 +6,11 @@ import (
 	"github.com/lejianwen/rustdesk-api/v2/service"
 )
 
-// BackendUserAuth 后台权限验证中间件
+// BackendUserAuth backend permission verification middleware
 func BackendUserAuth() gin.HandlerFunc {
 	return func(c *gin.Context) {
 
-		//测试先关闭
+		//disabled for testing
 		token := c.GetHeader("api-token")
 		if token == "" {
 			response.Fail(c, 403, response.TranslateMsg(c, "NeedLogin"))
@@ -34,7 +34,7 @@ func BackendUserAuth() gin.HandlerFunc {
 
 		c.Set("curUser", user)
 		c.Set("token", token)
-		//如果时间小于1天,token自动续期
+		// if the remaining time is less than 1 day, the token is auto-renewed
 		service.AllService.UserService.AutoRefreshAccessToken(ut)
 
 		c.Next()