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/context-store/components/MainContextStoreProvider.tsx

@@ -10,13 +10,14 @@ import { coreViewsState } from '@/views/states/coreViewState';
 import { useLocation, useParams, useSearchParams } from 'react-router-dom';
 import { AppPath } from 'twenty-shared/types';
 import { isDefined } from 'twenty-shared/utils';
-import { ViewKey } from '~/generated-metadata/graphql';
+import { ViewKey, ViewType } from '~/generated-metadata/graphql';
 import { isMatchingLocation } from '~/utils/isMatchingLocation';
 
 const getViewId = (
   viewIdFromQueryParams: string | null,
   indexViewId?: string,
   lastVisitedViewId?: string,
+  firstAvailableViewId?: string,
 ) => {
   if (isDefined(viewIdFromQueryParams)) {
     return viewIdFromQueryParams;
@@ -30,6 +31,10 @@ const getViewId = (
     return indexViewId;
   }
 
+  if (isDefined(firstAvailableViewId)) {
+    return firstAvailableViewId;
+  }
+
   return undefined;
 };
 
@@ -46,7 +51,7 @@ export const MainContextStoreProvider = () => {
   const objectNameSingular = useParams().objectNameSingular ?? '';
 
   const [searchParams] = useSearchParams();
-  const viewIdQueryParam = searchParams.get('viewId');
+  const viewIdQueryParamRaw = searchParams.get('viewId');
 
   const objectMetadataItems = useAtomStateValue(objectMetadataItemsState);
   const metadataStore = useAtomFamilyStateValue(metadataStoreState, 'views');
@@ -60,17 +65,49 @@ export const MainContextStoreProvider = () => {
 
   const { getLastVisitedViewIdFromObjectNamePlural } = useLastVisitedView();
 
-  const lastVisitedViewId = getLastVisitedViewIdFromObjectNamePlural(
+  const viewIdQueryParamView = coreViews.find(
+    (view) => view.id === viewIdQueryParamRaw,
+  );
+
+  const viewIdQueryParam =
+    isDefined(viewIdQueryParamView) &&
+    viewIdQueryParamView.type !== ViewType.FIELDS_WIDGET
+      ? viewIdQueryParamRaw
+      : null;
+
+  const lastVisitedViewIdRaw = getLastVisitedViewIdFromObjectNamePlural(
     objectMetadataItem?.namePlural ?? '',
   );
 
+  const lastVisitedView = coreViews.find(
+    (view) => view.id === lastVisitedViewIdRaw,
+  );
+
+  const lastVisitedViewId =
+    isDefined(lastVisitedView) &&
+    lastVisitedView.type !== ViewType.FIELDS_WIDGET
+      ? lastVisitedViewIdRaw
+      : undefined;
+
   const indexViewId = coreViews.find(
     (view) =>
       view.objectMetadataId === objectMetadataItem?.id &&
       view.key === ViewKey.INDEX,
   )?.id;
 
-  const viewId = getViewId(viewIdQueryParam, indexViewId, lastVisitedViewId);
+  const firstAvailableViewId = coreViews.find(
+    (view) =>
+      view.objectMetadataId === objectMetadataItem?.id &&
+      view.type !== ViewType.FIELDS_WIDGET,
+  )?.id;
+
+  const viewId = getViewId(
+    viewIdQueryParam,
+    indexViewId,
+    lastVisitedViewId,
+    firstAvailableViewId,
+  );
+
   const showAuthModal = useShowAuthModal();
 
   const shouldComputeContextStore =