fix: use direction enum for relation parsing

src/utils/cypher/converter/relation.ts

 import type { RelationStruct } from 'ts-common';
 import { getNodeCypher } from './node';
 import type { QueryCacheData } from './model';
+import { log } from 'ts-common/src/logger/logger';
 
 export const NoNodeError = new Error('relation must have a node');
 

src/utils/reactflow/query2backend.ts

@@ -14,7 +14,7 @@ import type {
 } from 'ts-common/src/model/graphology';
 import type { AllLogicStatement } from 'ts-common/src/model/query/logic/general';
 import { QueryElementTypes } from 'ts-common/src/model/reactflow';
-import { type QueryBuilderSettings, QueryUnionType } from 'ts-common/src/model/query/queryBuilderModel';
+import { type QueryBuilderSettings, QueryRelationDirection, QueryUnionType } from 'ts-common/src/model/query/queryBuilderModel';
 import { log } from '../../logger';
 
 // Chunk extraction: traverse graph to find all paths of logic between relations and entities
@@ -269,9 +269,9 @@ export function Query2BackendQuery(
         depth: _currNode.depth,
         direction: !_currNode.direction
           ? 'BOTH'
-          : _currNode.direction === 'right'
+          : _currNode.direction === QueryRelationDirection.RIGHT
           ? 'TO'
-          : _currNode.direction === 'left'
+          : _currNode.direction === QueryRelationDirection.LEFT
           ? 'FROM'
           : 'BOTH',
         node: chunk.length === position + 1 ? undefined : (processConnection(chunk, position + 1) as NodeStruct),