feat: initialize warpbox.dev project structure and backend

Initialize the repository with the core Go backend architecture and a frontend mockup for warpbox.dev, a self-hosted file-sharing application.

- Set up Go backend modules for configuration, HTTP server, middleware, handlers, and templates.
- Add local development scripts, environment templates, and basic project configuration.
- Include a React-based frontend mockup under the docs directory.

backend/libs/middleware/gzip.go

@@ -0,0 +1,69 @@
+package middleware
+
+import (
+	"compress/gzip"
+	"io"
+	"net/http"
+	"strings"
+)
+
+type gzipResponseWriter struct {
+	http.ResponseWriter
+	writer io.Writer
+	wrote  bool
+}
+
+func (w *gzipResponseWriter) WriteHeader(status int) {
+	if w.wrote {
+		return
+	}
+	w.wrote = true
+	header := w.Header()
+	header.Del("Content-Length")
+	header.Del("Accept-Ranges")
+	header.Set("Content-Encoding", "gzip")
+	header.Add("Vary", "Accept-Encoding")
+	w.ResponseWriter.WriteHeader(status)
+}
+
+func (w *gzipResponseWriter) Write(data []byte) (int, error) {
+	if !w.wrote {
+		w.WriteHeader(http.StatusOK)
+	}
+	return w.writer.Write(data)
+}
+
+func Gzip(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if !acceptsGzip(r) || shouldSkipGzip(r) {
+			next.ServeHTTP(w, r)
+			return
+		}
+
+		gz := gzip.NewWriter(w)
+		defer gz.Close()
+
+		next.ServeHTTP(&gzipResponseWriter{
+			ResponseWriter: w,
+			writer:         gz,
+		}, r)
+	})
+}
+
+func acceptsGzip(r *http.Request) bool {
+	return strings.Contains(r.Header.Get("Accept-Encoding"), "gzip")
+}
+
+func shouldSkipGzip(r *http.Request) bool {
+	if r.Method == http.MethodHead || r.Header.Get("Range") != "" {
+		return true
+	}
+
+	path := r.URL.Path
+	switch ext := strings.ToLower(path[strings.LastIndex(path, ".")+1:]); ext {
+	case "br", "gz", "zip", "7z", "rar", "jpg", "jpeg", "png", "gif", "webp", "avif", "mp4", "webm", "mov", "m4v", "mp3", "ogg", "woff", "woff2", "ttf", "otf":
+		return true
+	default:
+		return false
+	}
+}