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/command-menu-item/record/constants/DefaultRecordCommandMenuItemsConfig.tsx

@@ -116,8 +116,13 @@ export const DEFAULT_RECORD_COMMAND_MENU_ITEMS_CONFIG: Record<
     position: 2,
     isPinned: true,
     Icon: IconPlus,
-    shouldBeRegistered: ({ objectPermissions, hasAnySoftDeleteFilterOnView }) =>
-      (objectPermissions.canUpdateObjectRecords &&
+    shouldBeRegistered: ({
+      objectMetadataItem,
+      objectPermissions,
+      hasAnySoftDeleteFilterOnView,
+    }) =>
+      (!objectMetadataItem?.isSystem &&
+        objectPermissions.canUpdateObjectRecords &&
         !hasAnySoftDeleteFilterOnView) ??
       false,
     availableOn: [CommandMenuItemViewType.INDEX_PAGE_NO_SELECTION],
@@ -440,8 +445,10 @@ export const DEFAULT_RECORD_COMMAND_MENU_ITEMS_CONFIG: Record<
     Icon: IconFileImport,
     accent: 'default',
     isPinned: false,
-    shouldBeRegistered: ({ hasAnySoftDeleteFilterOnView }) =>
-      !hasAnySoftDeleteFilterOnView,
+    shouldBeRegistered: ({
+      objectMetadataItem,
+      hasAnySoftDeleteFilterOnView,
+    }) => !objectMetadataItem?.isSystem && !hasAnySoftDeleteFilterOnView,
     availableOn: [CommandMenuItemViewType.INDEX_PAGE_NO_SELECTION],
     component: <ImportRecordsNoSelectionRecordCommand />,
     requiredPermissionFlag: PermissionFlagType.IMPORT_CSV,