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/views/view-picker/components/ViewPickerEditButton.tsx

@@ -1,4 +1,7 @@
+import { useContextStoreObjectMetadataItemOrThrow } from '@/context-store/hooks/useContextStoreObjectMetadataItemOrThrow';
 import { useAtomComponentStateValue } from '@/ui/utilities/state/jotai/hooks/useAtomComponentStateValue';
+import { useAtomFamilySelectorValue } from '@/ui/utilities/state/jotai/hooks/useAtomFamilySelectorValue';
+import { coreViewsFromObjectMetadataItemFamilySelector } from '@/views/states/selectors/coreViewsFromObjectMetadataItemFamilySelector';
 import { ViewType } from '@/views/types/ViewType';
 import { useCreateViewFromCurrentState } from '@/views/view-picker/hooks/useCreateViewFromCurrentState';
 import { useDestroyViewFromCurrentState } from '@/views/view-picker/hooks/useDestroyViewFromCurrentState';
@@ -14,6 +17,15 @@ export const ViewPickerEditButton = () => {
   const { availableFieldsForGrouping, navigateToSelectSettings } =
     useGetAvailableFieldsToGroupRecordsBy();
 
+  const { objectMetadataItem } = useContextStoreObjectMetadataItemOrThrow();
+
+  const viewsOnCurrentObject = useAtomFamilySelectorValue(
+    coreViewsFromObjectMetadataItemFamilySelector,
+    { objectMetadataItemId: objectMetadataItem.id },
+  );
+
+  const isLastView = viewsOnCurrentObject.length <= 1;
+
   const { viewPickerMode } = useViewPickerMode();
   const viewPickerType = useAtomComponentStateValue(
     viewPickerTypeComponentState,
@@ -39,7 +51,7 @@ export const ViewPickerEditButton = () => {
         justify="center"
         focus={false}
         variant="secondary"
-        disabled={viewPickerIsPersisting}
+        disabled={viewPickerIsPersisting || isLastView}
       />
     );
   }

packages/twenty-front/src/modules/views/view-picker/components/ViewPickerListContent.tsx

@@ -50,6 +50,8 @@ export const ViewPickerListContent = () => {
     (view) => view.visibility === ViewVisibility.UNLISTED,
   );
 
+  const isLastView = viewsOnCurrentObject.length <= 1;
+
   const shouldShowSectionLabels =
     workspaceViews.length > 0 && unlistedViews.length > 0;
 
@@ -155,6 +157,7 @@ export const ViewPickerListContent = () => {
                         view={{ ...view, __typename: 'View' }}
                         handleViewSelect={handleViewSelect}
                         isIndexView={isIndexView}
+                        isLastView={isLastView}
                         onEdit={handleEditViewButtonClick}
                       />
                     }
@@ -187,6 +190,7 @@ export const ViewPickerListContent = () => {
                         view={{ ...view, __typename: 'View' }}
                         handleViewSelect={handleViewSelect}
                         isIndexView={isIndexView}
+                        isLastView={isLastView}
                         onEdit={handleEditViewButtonClick}
                       />
                     }

packages/twenty-front/src/modules/views/view-picker/components/ViewPickerOptionDropdown.tsx

@@ -30,6 +30,7 @@ import {
 
 type ViewPickerOptionDropdownProps = {
   isIndexView: boolean;
+  isLastView: boolean;
   view: Pick<
     View,
     | 'id'
@@ -45,6 +46,7 @@ type ViewPickerOptionDropdownProps = {
 
 export const ViewPickerOptionDropdown = ({
   isIndexView,
+  isLastView,
   onEdit,
   view,
   handleViewSelect,
@@ -149,12 +151,14 @@ export const ViewPickerOptionDropdown = ({
                           closeDropdown(dropdownId);
                         }}
                       />
-                      <MenuItem
-                        LeftIcon={IconTrash}
-                        text={t`Delete`}
-                        onClick={handleDelete}
-                        accent="danger"
-                      />
+                      {!isLastView && (
+                        <MenuItem
+                          LeftIcon={IconTrash}
+                          text={t`Delete`}
+                          onClick={handleDelete}
+                          accent="danger"
+                        />
+                      )}
                     </>
                   )}
                 </>

packages/twenty-front/src/modules/views/view-picker/hooks/useDestroyViewFromCurrentState.ts

@@ -60,12 +60,16 @@ export const useDestroyViewFromCurrentState = (viewBarInstanceId?: string) => {
 
     const shouldChangeView = viewPickerReferenceViewId === currentView?.id;
 
+    const remainingViews = viewsOnCurrentObject.filter(
+      (view) => view.id !== viewPickerReferenceViewId,
+    );
+
+    if (remainingViews.length === 0) {
+      return;
+    }
+
     if (shouldChangeView) {
-      changeView(
-        viewsOnCurrentObject.filter(
-          (view) => view.id !== viewPickerReferenceViewId,
-        )[0].id,
-      );
+      changeView(remainingViews[0].id);
     }
 
     store.set(