Release model context fix and branching feature

services/llm-api/internal/domain/conversation/conversation.go

@@ -119,6 +119,11 @@ type ConversationRepository interface {
 	// TODO: Implement forking functionality for conversation editing
 	ForkBranch(ctx context.Context, conversationID uint, sourceBranch, newBranch string, fromItemID string, description *string) error
 
+	// SwapBranchToMain swaps a branch with MAIN - the given branch becomes MAIN
+	// and the old MAIN is renamed to a backup branch name. This is used for edit/regenerate
+	// operations where the new content should become the primary conversation.
+	SwapBranchToMain(ctx context.Context, conversationID uint, branchToPromote string) (oldMainBackupName string, err error)
+
 	// Item rating operations - TODO: Implement item rating/feedback system
 	RateItem(ctx context.Context, conversationID uint, itemID string, rating ItemRating, comment *string) error
 	GetItemRating(ctx context.Context, conversationID uint, itemID string) (*ItemRating, error)
@@ -299,8 +304,22 @@ func (c *Conversation) CreateBranch(newBranchName, sourceBranch, fromItemID stri
 	return nil
 }
 
+// CreateBranchMetadata creates metadata for a new branch
+func (c *Conversation) CreateBranchMetadata(name string, parentBranch *string, forkFromItemID *string, description *string) BranchMetadata {
+	now := time.Now()
+	return BranchMetadata{
+		Name:             name,
+		Description:      description,
+		ParentBranch:     parentBranch,
+		ForkedAt:         &now,
+		ForkedFromItemID: forkFromItemID,
+		ItemCount:        0,
+		CreatedAt:        now,
+		UpdatedAt:        now,
+	}
+}
+
 // GenerateEditBranchName generates a unique branch name for conversation edits
-// TODO: Currently unused - will be needed when implementing conversation branching UI
 func GenerateEditBranchName(conversationID uint) string {
 	return fmt.Sprintf("EDIT_%d_%d", conversationID, time.Now().Unix())
 }

services/llm-api/internal/domain/conversation/conversation_service.go

@@ -200,9 +200,17 @@ func (s *ConversationService) AddItemsToConversation(ctx context.Context, conv *
 		return []Item{}, nil
 	}
 
-	// Validate branch exists (for now, only MAIN is supported)
+	// Default to MAIN branch if not specified
+	if branchName == "" {
+		branchName = BranchMain
+	}
+
+	// Validate branch exists for non-MAIN branches
 	if branchName != BranchMain {
-		return nil, platformerrors.NewError(ctx, platformerrors.LayerDomain, platformerrors.ErrorTypeNotFound, fmt.Sprintf("branch not found: %s", branchName), nil, "e5f6a7b8-c9d0-4e1f-2a3b-4c5d6e7f8a9b")
+		branch, err := s.repo.GetBranch(ctx, conv.ID, branchName)
+		if err != nil || branch == nil {
+			return nil, platformerrors.NewError(ctx, platformerrors.LayerDomain, platformerrors.ErrorTypeNotFound, fmt.Sprintf("branch not found: %s", branchName), nil, "e5f6a7b8-c9d0-4e1f-2a3b-4c5d6e7f8a9b")
+		}
 	}
 
 	// Get current item count to determine starting sequence number
@@ -229,15 +237,9 @@ func (s *ConversationService) AddItemsToConversation(ctx context.Context, conv *
 		itemPtrs[i] = &items[i]
 	}
 
-	// Add items to repository
-	if branchName == BranchMain || branchName == "" {
-		if err := s.repo.BulkAddItems(ctx, conv.ID, itemPtrs); err != nil {
-			return nil, platformerrors.AsError(ctx, platformerrors.LayerDomain, err, "failed to add items")
-		}
-	} else {
-		if err := s.repo.BulkAddItemsToBranch(ctx, conv.ID, branchName, itemPtrs); err != nil {
-			return nil, platformerrors.AsError(ctx, platformerrors.LayerDomain, err, "failed to add items to branch")
-		}
+	// Add items to repository - use branch-aware method for all branches
+	if err := s.repo.BulkAddItemsToBranch(ctx, conv.ID, branchName, itemPtrs); err != nil {
+		return nil, platformerrors.AsError(ctx, platformerrors.LayerDomain, err, "failed to add items to branch")
 	}
 
 	// Update conversation's updated_at timestamp

services/llm-api/internal/domain/conversation/item.go

@@ -684,6 +684,7 @@ type ItemFilter struct {
 	ConversationID *uint
 	Role           *ItemRole
 	ResponseID     *uint
+	Branch         *string // Filter by branch name
 }
 
 type ItemRepository interface {