Disable reset to default when custom tab or widget (#19814)

## Context
"Reset to default" action is rejected by the backend for custom entities
because there is no "default" concept for them

## Implementation
Grey out the Reset to default action on record page-layout tabs and
widgets when the entity either has no applicationId yet (unsaved draft —
previously slipped through the existing check), or belongs to the
workspace custom application.

<img width="926" height="370" alt="Screenshot 2026-04-17 at 18 50 31"
src="https://github.com/user-attachments/assets/c7c163f4-17a6-4b69-a66d-90f9085d27a2"
/>

packages/twenty-client-sdk/src/metadata/generated/schema.graphql

@@ -890,6 +890,7 @@ type GridPosition {
 
 type PageLayoutWidget {
   id: UUID!
+  applicationId: UUID!
   pageLayoutTabId: UUID!
   title: String!
   type: WidgetType!

packages/twenty-client-sdk/src/metadata/generated/schema.ts

@@ -664,6 +664,7 @@ export interface GridPosition {
 
 export interface PageLayoutWidget {
     id: Scalars['UUID']
+    applicationId: Scalars['UUID']
     pageLayoutTabId: Scalars['UUID']
     title: Scalars['String']
     type: WidgetType
@@ -3886,6 +3887,7 @@ export interface GridPositionGenqlSelection{
 
 export interface PageLayoutWidgetGenqlSelection{
     id?: boolean | number
+    applicationId?: boolean | number
     pageLayoutTabId?: boolean | number
     title?: boolean | number
     type?: boolean | number

packages/twenty-client-sdk/src/metadata/generated/types.ts

@@ -1873,6 +1873,9 @@ export default {
             "id": [
                 3
             ],
+            "applicationId": [
+                3
+            ],
             "pageLayoutTabId": [
                 3
             ],