refactor: redesign planos interface with design system patterns

- Create CreatePlanModal component with Headless UI Dialog
- Implement dark mode support throughout plans UI
- Update plans/page.tsx with professional card layout
- Update plans/[id]/page.tsx with consistent styling
- Add proper spacing, typography, and color consistency
- Implement smooth animations and transitions
- Add success/error message feedback
- Improve form UX with better input styling

backend/internal/api/handlers/files.go

@@ -39,6 +39,23 @@ func (h *FilesHandler) ServeFile(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	// Whitelist de buckets públicos permitidos
+	allowedBuckets := map[string]bool{
+		"aggios-logos": true,
+	}
+	if !allowedBuckets[bucket] {
+		log.Printf("🚫 Access denied to bucket: %s", bucket)
+		http.Error(w, "Access denied", http.StatusForbidden)
+		return
+	}
+
+	// Proteção contra path traversal
+	if strings.Contains(filePath, "..") {
+		log.Printf("🚫 Path traversal attempt detected: %s", filePath)
+		http.Error(w, "Invalid path", http.StatusBadRequest)
+		return
+	}
+
 	log.Printf("📁 Serving file: bucket=%s, path=%s", bucket, filePath)
 
 	// Initialize MinIO client