docs(gateway): gateway 剩余文件注释改中文（逐行 1:1，代码零字节改动）

主人 2026-10-03 拍板「注释一律中文」；gateway 至此整包注释中文化完成（本会话共 3 批：
已推库 16 个文件 + 本批剩余文件）。
校验：机械校验（非注释改动行）= 空；剥注释后代码文本逐行比对全等（不一致文件数 0）；
全树 go test ./... 58 包 ok / 0 FAIL；交叉编译绿。

internal/services/gateway/middleware.go

@@ -10,9 +10,9 @@ import (
 	apperr "git.yeij.top/AskaEth/Cyrene_v2/internal/errors"
 )
 
-// cors sets the Access-Control-* headers for origins in the configured allow
-// list and short-circuits OPTIONS preflight requests. An empty origin (same-origin
-// or non-browser client) is passed through untouched.
+// cors 为已配置允许列表中的来源设置 Access-Control-* 头，并
+// 短路 OPTIONS 预检请求。空来源（同源或
+// 非浏览器客户端）原样放行。
 func (s *Server) cors(next http.Handler) http.Handler {
 	allowed, allowAll := s.allowedOrigins()
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
@@ -36,8 +36,8 @@ func (s *Server) cors(next http.Handler) http.Handler {
 	})
 }
 
-// allowedOrigins resolves the configured origin list into a lookup set plus an
-// allow-all flag for the "*" wildcard.
+// allowedOrigins 把已配置的来源列表解析成查找集合，外加针对
+// "*" 通配符的允许全部标志。
 func (s *Server) allowedOrigins() (map[string]bool, bool) {
 	list := s.cfg.AllowedOrigins
 	if len(list) == 0 {
@@ -55,8 +55,8 @@ func (s *Server) allowedOrigins() (map[string]bool, bool) {
 	return out, allowAll
 }
 
-// recover converts a panic in a downstream handler into a 500 {error:...}
-// response instead of crashing the process, and logs the panic.
+// recover 把下游 handler 中的 panic 转成 500 {error:...}
+// 响应，而不是让进程崩溃，并记录该 panic。
 func (s *Server) recover(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		defer func() {
@@ -69,7 +69,7 @@ func (s *Server) recover(next http.Handler) http.Handler {
 	})
 }
 
-// logging records one structured line per request (method, path, status, dur).
+// logging 为每个请求记录一行结构化日志（method、path、status、dur）。
 func (s *Server) logging(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		start := time.Now()
@@ -86,21 +86,21 @@ func (s *Server) logging(next http.Handler) http.Handler {
 	})
 }
 
-// statusRecorder captures the written status so the logging middleware can report
-// it. It forwards the optional Hijacker/Flusher interfaces so the WebSocket
-// upgrader (which requires http.Hijacker) and streaming handlers still work.
+// statusRecorder 捕获写入的状态，使 logging 中间件能报告
+// 它。它转发可选的 Hijacker/Flusher 接口，因此 WebSocket
+// 升级器（要求 http.Hijacker）与流式 handler 仍能工作。
 type statusRecorder struct {
 	http.ResponseWriter
 	status int
 }
 
-// WriteHeader records the status before delegating.
+// WriteHeader 在委托之前记录状态。
 func (r *statusRecorder) WriteHeader(code int) {
 	r.status = code
 	r.ResponseWriter.WriteHeader(code)
 }
 
-// Hijack forwards to the underlying writer when it supports connection hijacking.
+// Hijack 在底层 writer 支持连接劫持时转发给它。
 func (r *statusRecorder) Hijack() (net.Conn, *bufio.ReadWriter, error) {
 	if hj, ok := r.ResponseWriter.(http.Hijacker); ok {
 		return hj.Hijack()
@@ -108,7 +108,7 @@ func (r *statusRecorder) Hijack() (net.Conn, *bufio.ReadWriter, error) {
 	return nil, nil, fmt.Errorf("gateway: hijack unsupported by %T", r.ResponseWriter)
 }
 
-// Flush forwards to the underlying writer when it supports flushing.
+// Flush 在底层 writer 支持 flush 时转发给它。
 func (r *statusRecorder) Flush() {
 	if f, ok := r.ResponseWriter.(http.Flusher); ok {
 		f.Flush()