feat: implement multi-library support for GetRandomSongs, GetSongsByGenre, GetStarred, and GetStarred2

- Added multi-library filtering to GetRandomSongs endpoint using musicFolderId parameter
- Added multi-library filtering to GetSongsByGenre endpoint using musicFolderId parameter
- Enhanced GetStarred and GetStarred2 to filter artists, albums, and songs by library
- Added Options field to MockMediaFileRepo and MockArtistRepo for test compatibility
- Added comprehensive Ginkgo/Gomega tests for all new multi-library functionality
- All tests verify proper SQL filter generation and library access validation
- Supports single/multiple musicFolderId values with fallback to all accessible libraries

tests/mock_artist_repo.go

@@ -16,8 +16,9 @@ func CreateMockArtistRepo() *MockArtistRepo {
 
 type MockArtistRepo struct {
 	model.ArtistRepository
-	Data map[string]*model.Artist
-	Err  bool
+	Data    map[string]*model.Artist
+	Err     bool
+	Options model.QueryOptions
 }
 
 func (m *MockArtistRepo) SetError(err bool) {
@@ -73,6 +74,9 @@ func (m *MockArtistRepo) IncPlayCount(id string, timestamp time.Time) error {
 }
 
 func (m *MockArtistRepo) GetAll(options ...model.QueryOptions) (model.Artists, error) {
+	if len(options) > 0 {
+		m.Options = options[0]
+	}
 	if m.Err {
 		return nil, errors.New("mock repo error")
 	}

tests/mock_mediafile_repo.go

@@ -27,6 +27,7 @@ type MockMediaFileRepo struct {
 	CountAllValue         int64
 	CountAllOptions       model.QueryOptions
 	DeleteAllMissingValue int64
+	Options               model.QueryOptions
 }
 
 func (m *MockMediaFileRepo) SetError(err bool) {
@@ -72,7 +73,10 @@ func (m *MockMediaFileRepo) GetWithParticipants(id string) (*model.MediaFile, er
 	return nil, model.ErrNotFound
 }
 
-func (m *MockMediaFileRepo) GetAll(...model.QueryOptions) (model.MediaFiles, error) {
+func (m *MockMediaFileRepo) GetAll(qo ...model.QueryOptions) (model.MediaFiles, error) {
+	if len(qo) > 0 {
+		m.Options = qo[0]
+	}
 	if m.Err {
 		return nil, errors.New("error")
 	}