morph backend CORE api (#13517)

# Morph Relation needs some work on the core API

Especially on the Morph types

<img width="682" height="394" alt="Screenshot 2025-07-31 at 12 19 40"
src="https://github.com/user-attachments/assets/8b185ae3-3fe7-4886-97b1-ec143bb1b0f4"
/>


## Focus Areas:
- GraphQL schema generation
- Query parsing and field selection
- Morph relation field support
- Input type definition preparation

packages/twenty-server/src/engine/metadata-modules/field-metadata/utils/compute-morph-relation-field-name.util.ts

@@ -0,0 +1,32 @@
+import { capitalize } from 'twenty-shared/utils';
+
+import { RelationType } from 'src/engine/metadata-modules/field-metadata/interfaces/relation-type.interface';
+
+import { type ObjectMetadataEntity } from 'src/engine/metadata-modules/object-metadata/object-metadata.entity';
+
+type ComputeMorphRelationFieldNameArgs = {
+  fieldName: string;
+  relationDirection: RelationType;
+  targetObjectMetadata: Pick<
+    ObjectMetadataEntity,
+    'nameSingular' | 'namePlural'
+  >;
+};
+
+export const computeMorphRelationFieldName = ({
+  fieldName,
+  relationDirection,
+  targetObjectMetadata,
+}: ComputeMorphRelationFieldNameArgs): string => {
+  if (relationDirection === RelationType.MANY_TO_ONE) {
+    return `${fieldName}${capitalize(targetObjectMetadata.nameSingular)}`;
+  }
+
+  if (relationDirection === RelationType.ONE_TO_MANY) {
+    return `${fieldName}${capitalize(targetObjectMetadata.namePlural)}`;
+  }
+
+  throw new Error(
+    `Invalid relation direction: ${relationDirection} for field ${fieldName}`,
+  );
+};

packages/twenty-server/src/engine/metadata-modules/utils/generate-object-metadata-maps.util.ts

@@ -20,7 +20,14 @@ export const generateObjectMetadataMaps = (
 
     for (const fieldMetadata of objectMetadata.fields) {
       if (
-        isFieldMetadataEntityOfType(fieldMetadata, FieldMetadataType.RELATION)
+        isFieldMetadataEntityOfType(
+          fieldMetadata,
+          FieldMetadataType.RELATION,
+        ) ||
+        isFieldMetadataEntityOfType(
+          fieldMetadata,
+          FieldMetadataType.MORPH_RELATION,
+        )
       ) {
         if (fieldMetadata.settings?.joinColumnName) {
           fieldIdByJoinColumnNameMap[fieldMetadata.settings.joinColumnName] =