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_test.go

@@ -0,0 +1,63 @@
+package middleware
+
+import (
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestGzipCompressesEligibleResponses(t *testing.T) {
+	handler := Gzip(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Length", "11")
+		_, _ = io.WriteString(w, "hello world")
+	}))
+
+	request := httptest.NewRequest(http.MethodGet, "/page", nil)
+	request.Header.Set("Accept-Encoding", "gzip")
+	response := httptest.NewRecorder()
+
+	handler.ServeHTTP(response, request)
+
+	if got := response.Header().Get("Content-Encoding"); got != "gzip" {
+		t.Fatalf("Content-Encoding = %q, want gzip", got)
+	}
+	if got := response.Header().Get("Content-Length"); got != "" {
+		t.Fatalf("Content-Length = %q, want empty for gzipped response", got)
+	}
+	if got := response.Header().Get("Vary"); got != "Accept-Encoding" {
+		t.Fatalf("Vary = %q, want Accept-Encoding", got)
+	}
+}
+
+func TestGzipSkipsRangeAndHeadRequests(t *testing.T) {
+	handler := Gzip(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		_, _ = io.WriteString(w, "hello world")
+	}))
+
+	tests := []struct {
+		name        string
+		method      string
+		rangeHeader string
+	}{
+		{name: "range", method: http.MethodGet, rangeHeader: "bytes=0-4"},
+		{name: "head", method: http.MethodHead},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			request := httptest.NewRequest(tt.method, "/asset.css", nil)
+			request.Header.Set("Accept-Encoding", "gzip")
+			if tt.rangeHeader != "" {
+				request.Header.Set("Range", tt.rangeHeader)
+			}
+			response := httptest.NewRecorder()
+
+			handler.ServeHTTP(response, request)
+
+			if got := response.Header().Get("Content-Encoding"); got != "" {
+				t.Fatalf("Content-Encoding = %q, want empty", got)
+			}
+		})
+	}
+}