fix(preference): update legacy handlers to return ValueTitle and InputOptions

- Add ValueTitle, ScopeType, ScopeId to transformPreferenceToPB
- Add InputOptions to transformPreferenceTraitToPB
- Update ListUserPreferences and ListCurrentUserPreferences to use
  LoadUserPreferences for consistent behavior with ConnectRPC handlers
- Add LoadUserPreferences to PreferenceService interface

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: whoAbhishekSah

internal/api/v1beta1/mocks/preference_service.go

@@ -16,6 +16,7 @@ type PreferenceService interface {
 	Create(ctx context.Context, preference preference.Preference) (preference.Preference, error)
 	Describe(ctx context.Context) []preference.Trait
 	List(ctx context.Context, filter preference.Filter) ([]preference.Preference, error)
+	LoadUserPreferences(ctx context.Context, filter preference.Filter) ([]preference.Preference, error)
 	LoadPlatformPreferences(ctx context.Context) (map[string]string, error)
 }
 
@@ -162,8 +163,14 @@ func (h Handler) CreateUserPreferences(ctx context.Context, request *frontierv1b
 }
 
 func (h Handler) ListUserPreferences(ctx context.Context, request *frontierv1beta1.ListUserPreferencesRequest) (*frontierv1beta1.ListUserPreferencesResponse, error) {
-	prefs, err := h.preferenceService.List(ctx, preference.Filter{
-		UserID: request.GetId(),
+	// LoadUserPreferences returns complete preference set with priority:
+	// 1. Scoped DB values (if scope provided)
+	// 2. Global DB values
+	// 3. Trait defaults
+	prefs, err := h.preferenceService.LoadUserPreferences(ctx, preference.Filter{
+		UserID:    request.GetId(),
+		ScopeType: request.GetScopeType(),
+		ScopeID:   request.GetScopeId(),
 	})
 	if err != nil {
 		return nil, status.Errorf(codes.Internal, err.Error())
@@ -217,8 +224,14 @@ func (h Handler) ListCurrentUserPreferences(ctx context.Context, request *fronti
 	if err != nil {
 		return nil, err
 	}
-	prefs, err := h.preferenceService.List(ctx, preference.Filter{
-		UserID: principal.ID,
+	// LoadUserPreferences returns complete preference set with priority:
+	// 1. Scoped DB values (if scope provided)
+	// 2. Global DB values
+	// 3. Trait defaults
+	prefs, err := h.preferenceService.LoadUserPreferences(ctx, preference.Filter{
+		UserID:    principal.ID,
+		ScopeType: request.GetScopeType(),
+		ScopeID:   request.GetScopeId(),
 	})
 	if err != nil {
 		return nil, status.Errorf(codes.Internal, err.Error())
@@ -242,8 +255,11 @@ func transformPreferenceToPB(pref preference.Preference) *frontierv1beta1.Prefer
 		Id:           pref.ID,
 		Name:         pref.Name,
 		Value:        pref.Value,
+		ValueTitle:   pref.ValueTitle,
 		ResourceId:   pref.ResourceID,
 		ResourceType: pref.ResourceType,
+		ScopeType:    pref.ScopeType,
+		ScopeId:      pref.ScopeID,
 		CreatedAt:    timestamppb.New(pref.CreatedAt),
 		UpdatedAt:    timestamppb.New(pref.UpdatedAt),
 	}
@@ -262,6 +278,15 @@ func transformPreferenceTraitToPB(pref preference.Trait) *frontierv1beta1.Prefer
 		InputHints:      pref.InputHints,
 		Default:         pref.Default,
 	}
+
+	// Convert InputOptions to proto
+	for _, opt := range pref.InputOptions {
+		pbTrait.InputOptions = append(pbTrait.InputOptions, &frontierv1beta1.InputHintOption{
+			Name:  opt.Name,
+			Title: opt.Title,
+		})
+	}
+
 	switch pref.Input {
 	case preference.TraitInputText:
 		pbTrait.InputType = frontierv1beta1.PreferenceTrait_INPUT_TYPE_TEXT