feat: init mirror-proxy project

- Docker Hub / GHCR / GitHub reverse proxy
- Web admin panel with link management
- Dynamic admin path, user and password config
- Rate limiting per link (dual/single auth mode)
- Docker and docker-compose deployment support
- GitHub Actions workflow for auto-publish to GHCR

internal/middleware/middleware.go

@@ -0,0 +1,74 @@
+package middleware
+
+import (
+	"net/http"
+	"strings"
+	"time"
+)
+
+// CORS 跨域中间件
+func CORS(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Access-Control-Allow-Origin", "*")
+		w.Header().Set("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS, HEAD, PATCH")
+		w.Header().Set("Access-Control-Allow-Headers", "Authorization, Content-Type, Accept, Origin, X-Requested-With")
+		w.Header().Set("Access-Control-Expose-Headers", "Content-Length, Content-Type, X-Docker-Token")
+		w.Header().Set("Access-Control-Max-Age", "86400")
+
+		if r.Method == "OPTIONS" {
+			w.WriteHeader(http.StatusOK)
+			return
+		}
+
+		next.ServeHTTP(w, r)
+	})
+}
+
+// Logger 日志中间件
+func Logger(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		start := time.Now()
+		wrapped := &responseWriter{ResponseWriter: w, statusCode: http.StatusOK}
+		next.ServeHTTP(wrapped, r)
+		// 简单日志输出
+		_ = start
+	})
+}
+
+type responseWriter struct {
+	http.ResponseWriter
+	statusCode int
+}
+
+func (rw *responseWriter) WriteHeader(code int) {
+	rw.statusCode = code
+	rw.ResponseWriter.WriteHeader(code)
+}
+
+// BasicAuth 基础认证中间件
+func BasicAuth(username, password string) func(http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			user, pass, ok := r.BasicAuth()
+			if !ok || user != username || pass != password {
+				w.Header().Set("WWW-Authenticate", `Basic realm="Admin Panel"`)
+				http.Error(w, "Unauthorized", http.StatusUnauthorized)
+				return
+			}
+			next.ServeHTTP(w, r)
+		})
+	}
+}
+
+// StripPrefix 安全地移除路径前缀
+func StripPrefix(prefix string, h http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		p := strings.TrimPrefix(r.URL.Path, prefix)
+		if p == r.URL.Path {
+			http.NotFound(w, r)
+			return
+		}
+		r.URL.Path = p
+		h.ServeHTTP(w, r)
+	})
+}