scaffold record page layout + fields view when adding an object (#19977)

## Summary

Extends `yarn twenty add` → **Object** so it scaffolds a complete record
page out
of the box:

- A **record-page-fields view** (`<name>-record-page-fields.ts`,
FIELDS_WIDGET)
pre-populated with the `name` field plus the auto-generated default
fields (`createdAt`,
`updatedAt`, `createdBy`, `updatedBy`) — the default-field entries are
emitted as
`generateDefaultFieldUniversalIdentifier({ objectUniversalIdentifier,
fieldName: '...' })`
calls rather than pre-computed UUIDs, so the generated file
double-serves as
documentation for the public util.
- A **record page layout** (`<name>-record-page-layout.ts`) with a Home
tab whose Fields
widget points at the new view (via `viewUniversalIdentifier`), plus a
Timeline tab.
- The companion prompt now covers all three artefacts (was view + nav
menu item).

Fix: Server-side, renames `viewId` → `viewUniversalIdentifier` on the
universal-flat FIELDS
widget configuration so it is consistent with other universal-flat
references. The DB-side
DTO keeps `viewId` (now typed as `SerializedRelation`), and the
conversion utils map
between the two.

<img width="337" height="349" alt="Screenshot 2026-04-22 at 15 40 22"
src="https://github.com/user-attachments/assets/59e36540-1761-46b0-808d-648c68604268"
/>

packages/twenty-server/src/engine/workspace-manager/workspace-migration/workspace-migration-runner/action-handlers/page-layout-widget/services/utils/from-universal-configuration-to-flat-page-layout-widget-configuration.util.ts

@@ -255,11 +255,8 @@ export const fromUniversalConfigurationToFlatPageLayoutWidgetConfiguration = ({
     }
 
     case WidgetConfigurationType.FIELDS: {
-      const {
-        viewId: viewUniversalIdentifier,
-        newFieldDefaultVisibility,
-        ...rest
-      } = universalConfiguration;
+      const { viewUniversalIdentifier, newFieldDefaultVisibility, ...rest } =
+        universalConfiguration;
 
       let viewId: string | null = null;