feat: initial commit — backend API + student cabinet frontend

- Go backend: auth (JWT), points earn/spend, QR token generation,
  partners, admin grant/stats endpoints with chi router
- Next.js 14 frontend: login, student dashboard, transaction history,
  QR display, partners list
- PostgreSQL migrations (4 tables), Redis cache, Docker Compose
- CORS middleware, role-based route protection, Zustand auth store

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/internal/middleware/logger.go

@@ -0,0 +1,34 @@
+package middleware
+
+import (
+	"log/slog"
+	"net/http"
+	"time"
+)
+
+// Logger is structured request-logging middleware using log/slog.
+// It records method, path, status code, and response duration for every request.
+func Logger(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		start := time.Now()
+		wrapped := &responseWriter{ResponseWriter: w, status: http.StatusOK}
+		next.ServeHTTP(wrapped, r)
+		slog.Info("request",
+			"method", r.Method,
+			"path", r.URL.Path,
+			"status", wrapped.status,
+			"duration_ms", time.Since(start).Milliseconds(),
+		)
+	})
+}
+
+// responseWriter wraps http.ResponseWriter to capture the status code.
+type responseWriter struct {
+	http.ResponseWriter
+	status int
+}
+
+func (rw *responseWriter) WriteHeader(code int) {
+	rw.status = code
+	rw.ResponseWriter.WriteHeader(code)
+}