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/logger.go

@@ -0,0 +1,54 @@
+package middleware
+
+import (
+	"log/slog"
+	"net/http"
+	"time"
+)
+
+type statusRecorder struct {
+	http.ResponseWriter
+	status int
+	bytes  int
+}
+
+func (r *statusRecorder) WriteHeader(status int) {
+	r.status = status
+	r.ResponseWriter.WriteHeader(status)
+}
+
+func (r *statusRecorder) Write(data []byte) (int, error) {
+	if r.status == 0 {
+		r.status = http.StatusOK
+	}
+	n, err := r.ResponseWriter.Write(data)
+	r.bytes += n
+	return n, err
+}
+
+func Logger(logger *slog.Logger) Middleware {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			start := time.Now()
+			recorder := &statusRecorder{ResponseWriter: w}
+
+			next.ServeHTTP(recorder, r)
+
+			status := recorder.status
+			if status == 0 {
+				status = http.StatusOK
+			}
+
+			logger.Info("http request",
+				"method", r.Method,
+				"path", r.URL.Path,
+				"status", status,
+				"bytes", recorder.bytes,
+				"duration_ms", time.Since(start).Milliseconds(),
+				"request_id", RequestIDFromContext(r.Context()),
+				"remote_addr", r.RemoteAddr,
+				"user_agent", r.UserAgent(),
+			)
+		})
+	}
+}