chore(合并): 同步主分支变更并解决冲突

- 合并 wire/httpclient/http_upstream/proxy_probe 冲突并保留校验逻辑
- 引入 proxyutil 及测试，完善代理配置
- 更新 goreleaser/workflow 与前端细节调整

测试: go test ./...

backend/internal/handler/admin/proxy_handler.go

@@ -26,7 +26,7 @@ func NewProxyHandler(adminService service.AdminService) *ProxyHandler {
 // CreateProxyRequest represents create proxy request
 type CreateProxyRequest struct {
 	Name     string `json:"name" binding:"required"`
-	Protocol string `json:"protocol" binding:"required,oneof=http https socks5"`
+	Protocol string `json:"protocol" binding:"required,oneof=http https socks5 socks5h"`
 	Host     string `json:"host" binding:"required"`
 	Port     int    `json:"port" binding:"required,min=1,max=65535"`
 	Username string `json:"username"`
@@ -36,7 +36,7 @@ type CreateProxyRequest struct {
 // UpdateProxyRequest represents update proxy request
 type UpdateProxyRequest struct {
 	Name     string `json:"name"`
-	Protocol string `json:"protocol" binding:"omitempty,oneof=http https socks5"`
+	Protocol string `json:"protocol" binding:"omitempty,oneof=http https socks5 socks5h"`
 	Host     string `json:"host"`
 	Port     int    `json:"port" binding:"omitempty,min=1,max=65535"`
 	Username string `json:"username"`
@@ -255,7 +255,7 @@ func (h *ProxyHandler) GetProxyAccounts(c *gin.Context) {
 
 // BatchCreateProxyItem represents a single proxy in batch create request
 type BatchCreateProxyItem struct {
-	Protocol string `json:"protocol" binding:"required,oneof=http https socks5"`
+	Protocol string `json:"protocol" binding:"required,oneof=http https socks5 socks5h"`
 	Host     string `json:"host" binding:"required"`
 	Port     int    `json:"port" binding:"required,min=1,max=65535"`
 	Username string `json:"username"`