Add system view fallback (#18536)

## Context
The goal is to add a "See records" button in all objects that would
redirect to that view (this will be done in a later PR). See screenshot
below.
<img width="665" height="312" alt="Screenshot 2026-03-10 at 15 54 36"
src="https://github.com/user-attachments/assets/6e23a75b-cff0-4d93-bce8-b5481b05c6f6"
/>

## Implementation
- If a view does not exist on an object, there is a **temporary**
fallback where the frontend creates the missing view as a custom view
when going over the object index page
- System objects are now surfaced but we don't want their records to be
editable, they will be readonly (mostly, all fields will be non-editable
except for their custom fields).
- We can't create a new record of a system object, some actions are also
hidden.
- The backend now rejects if you are trying to delete the last view of
an object

packages/twenty-front/src/modules/page-layout/widgets/components/WidgetActionFieldEdit.tsx

@@ -108,6 +108,7 @@ export const WidgetActionFieldEdit = () => {
     isDisplayModeFixHeight: false,
     isRecordFieldReadOnly: isRecordFieldReadOnly({
       isRecordReadOnly,
+      isSystemObject: objectMetadataItem.isSystem,
       objectPermissions: getObjectPermissionsFromMapByObjectMetadataId({
         objectPermissionsByObjectMetadataId,
         objectMetadataId: objectMetadataItem.id,
@@ -115,6 +116,7 @@ export const WidgetActionFieldEdit = () => {
       fieldMetadataItem: {
         id: fieldMetadataItem.id,
         isUIReadOnly: fieldMetadataItem.isUIReadOnly ?? false,
+        isCustom: fieldMetadataItem.isCustom ?? false,
       },
     }),
     anchorId: recordFieldInputInstanceId,

packages/twenty-front/src/modules/page-layout/widgets/field/components/FieldWidgetDisplay.tsx

@@ -89,6 +89,7 @@ export const FieldWidgetDisplay = ({
                 isDisplayModeFixHeight: false,
                 isRecordFieldReadOnly: isRecordFieldReadOnly({
                   isRecordReadOnly,
+                  isSystemObject: objectMetadataItem.isSystem,
                   objectPermissions:
                     getObjectPermissionsFromMapByObjectMetadataId({
                       objectPermissionsByObjectMetadataId,
@@ -97,6 +98,7 @@ export const FieldWidgetDisplay = ({
                   fieldMetadataItem: {
                     id: fieldMetadataItem.id,
                     isUIReadOnly: fieldMetadataItem.isUIReadOnly ?? false,
+                    isCustom: fieldMetadataItem.isCustom ?? false,
                   },
                 }),
                 onMouseEnter: handleMouseEnter,

packages/twenty-front/src/modules/page-layout/widgets/fields/components/FieldsWidgetFieldItem.tsx

@@ -73,6 +73,7 @@ export const FieldsWidgetFieldItem = ({
         isDisplayModeFixHeight: true,
         isRecordFieldReadOnly: isRecordFieldReadOnly({
           isRecordReadOnly,
+          isSystemObject: objectMetadataItem.isSystem,
           objectPermissions: getObjectPermissionsFromMapByObjectMetadataId({
             objectPermissionsByObjectMetadataId,
             objectMetadataId: objectMetadataItem.id,
@@ -80,6 +81,7 @@ export const FieldsWidgetFieldItem = ({
           fieldMetadataItem: {
             id: fieldMetadataItem.id,
             isUIReadOnly: fieldMetadataItem.isUIReadOnly ?? false,
+            isCustom: fieldMetadataItem.isCustom ?? false,
           },
         }),
         onMouseEnter,

packages/twenty-front/src/modules/page-layout/widgets/hooks/useWidgetActions.ts

@@ -77,6 +77,7 @@ export const useWidgetActions = ({
 
   const isFieldReadOnly = isRecordFieldReadOnly({
     isRecordReadOnly,
+    isSystemObject: objectMetadataItem.isSystem,
     objectPermissions: getObjectPermissionsFromMapByObjectMetadataId({
       objectPermissionsByObjectMetadataId,
       objectMetadataId: objectMetadataItem.id,
@@ -84,6 +85,7 @@ export const useWidgetActions = ({
     fieldMetadataItem: {
       id: fieldMetadataItem.id,
       isUIReadOnly: fieldMetadataItem.isUIReadOnly ?? false,
+      isCustom: fieldMetadataItem.isCustom ?? false,
     },
   });