refactor backend packages and global db service

backend/internal/logic/files/service_test.go

@@ -0,0 +1,29 @@
+package files
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestSaveStoresFileUnderProjectDirectory(t *testing.T) {
+	service := NewService(t.TempDir())
+
+	stored, err := service.Save(12, "brief.md", strings.NewReader("hello"))
+
+	require.NoError(t, err)
+	require.Equal(t, "brief.md", stored.OriginalName)
+	require.Contains(t, stored.RelativePath, "projects/12/")
+	require.FileExists(t, stored.AbsolutePath)
+}
+
+func TestSaveNeutralizesPathTraversal(t *testing.T) {
+	service := NewService(t.TempDir())
+
+	stored, err := service.Save(12, "..\\..\\secret.txt", strings.NewReader("hello"))
+
+	require.NoError(t, err)
+	require.Equal(t, "secret.txt", stored.OriginalName)
+	require.Contains(t, stored.RelativePath, "projects/12/")
+}