fix: cannot create record from table view — empty morph to-many relation returns null (#21846)

## Problem

Creating a record from the table view (reproduced on **People**) crashes
the client even though the `createOne…` mutation succeeds server-side,
so the record never appears:

```
Cannot read properties of null (reading 'map')
  getRecordConnectionFromRecords → getRecordNodeFromRecord → optimistic cache effect → createOneRecord
```

## Root cause

An empty **morph** to-many relation comes back as `null`, while every
other to-many relation comes back as `{ edges: [] }`. The frontend then
runs `null.map` while building the optimistic cache node; the error
escapes the mutation `update`, the rollback evicts the record, and it
never lands in the table.

## Fix

**Server** — plain to-many relations are hydrated to `[]` and formatted
to `{ edges: [] }` by `ObjectRecordsToGraphqlConnectionHelper`; an empty
morph to-many was left undefined and the field was skipped (→ `null`).
Default an unset to-many value to `[]` so it goes through the **same
connection path as plain to-many relations**.

**Frontend** — defensive guard in `getRecordNodeFromRecord`: a to-many
relation whose value isn't an array is skipped instead of crashing,
mirroring the existing guard in `extractTargetRecordsFromRelation`.
Needed regardless, since cached data / SSE / older servers still send
`null`.

## Tests

- Unit: `getRecordNodeFromRecord` skips a null to-many (reproduces the
exact crash without the guard).
- Integration: an empty morph `ONE_TO_MANY` read returns `{ edges: []
}`, not null.

packages/twenty-server/src/engine/api/graphql/graphql-query-runner/helpers/object-records-to-graphql-connection.helper.ts

@@ -17,6 +17,7 @@ import {
 import { encodeCursor } from 'src/engine/api/graphql/graphql-query-runner/utils/cursors.util';
 import { getTargetObjectMetadataOrThrow } from 'src/engine/api/graphql/graphql-query-runner/utils/get-target-object-metadata.util';
 import { type AggregationField } from 'src/engine/api/graphql/workspace-schema-builder/utils/get-available-aggregations-from-object-fields.util';
+import { RelationType } from 'src/engine/metadata-modules/field-metadata/interfaces/relation-type.interface';
 import { type CompositeFieldMetadataType } from 'src/engine/metadata-modules/field-metadata/types/composite-field-metadata-type.type';
 import { isCompositeFieldMetadataType } from 'src/engine/metadata-modules/field-metadata/utils/is-composite-field-metadata-type.util';
 import { type FlatEntityMaps } from 'src/engine/metadata-modules/flat-entity/types/flat-entity-maps.type';
@@ -221,7 +222,13 @@ export class ObjectRecordsToGraphqlConnectionHelper {
             objectRecord[fieldMetadataNameWithId];
         }
 
-        const objectValue = objectRecord[fieldMetadata.name];
+        const isToManyRelation =
+          fieldMetadata.settings?.relationType === RelationType.ONE_TO_MANY;
+
+        const objectValue =
+          !isDefined(objectRecord[fieldMetadata.name]) && isToManyRelation
+            ? []
+            : objectRecord[fieldMetadata.name];
 
         if (!isDefined(objectValue)) {
           continue;