feat: support bulk file move in same dir

apps/backend/internal/virtualfs/hierarchical_key_resolver.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 
 	"github.com/get-drexa/drexa/internal/blob"
+	"github.com/google/uuid"
 	"github.com/uptrace/bun"
 )
 
@@ -38,3 +39,41 @@ func (r *HierarchicalKeyResolver) ResolveDeletionKeys(ctx context.Context, node
 	}
 	return &DeletionPlan{Prefix: blob.Key(path)}, nil
 }
+
+// ResolveBulkMoveOps computes blob move operations for nodes being moved to a new parent.
+// This implementation optimizes by computing parent paths only once (2 queries total),
+// rather than computing the full path for each node individually (N queries).
+func (r *HierarchicalKeyResolver) ResolveBulkMoveOps(ctx context.Context, db bun.IDB, nodes []*Node, newParentID uuid.UUID) ([]BlobMoveOp, error) {
+	if len(nodes) == 0 {
+		return nil, nil
+	}
+
+	accountID := nodes[0].AccountID
+	oldParentID := nodes[0].ParentID
+
+	for _, node := range nodes[1:] {
+		if node.ParentID != oldParentID {
+			return nil, ErrUnsupportedOperation
+		}
+	}
+
+	oldParentPath, err := buildPathFromNodeID(ctx, db, oldParentID)
+	if err != nil {
+		return nil, err
+	}
+
+	newParentPath, err := buildPathFromNodeID(ctx, db, newParentID)
+	if err != nil {
+		return nil, err
+	}
+
+	// For each node, construct old and new keys using the precomputed parent paths
+	ops := make([]BlobMoveOp, len(nodes))
+	for i, node := range nodes {
+		oldKey := blob.Key(fmt.Sprintf("%s/%s/%s", accountID, oldParentPath, node.Name))
+		newKey := blob.Key(fmt.Sprintf("%s/%s/%s", accountID, newParentPath, node.Name))
+		ops[i] = BlobMoveOp{OldKey: oldKey, NewKey: newKey}
+	}
+
+	return ops, nil
+}