fix inconsistent widget placeholder placement (#15580)

fixes -
https://github.com/twentyhq/twenty/pull/15496#issuecomment-3481636780

and https://discord.com/channels/1130383047699738754/1434971632539009055

- make the pending placeholder to be non-static -- so that it behaves
similarly to compact behavior like other widgets do
- make sure users can't set dashboards to be opened in the side panel --
similar to workflows

before- 


https://github.com/user-attachments/assets/d991db56-1388-4e4b-b743-a63f56b6187a

after- 


https://github.com/user-attachments/assets/9031f2c6-1e3b-4604-a5a0-3124d14484ce

packages/twenty-front/src/modules/object-record/utils/canOpenObjectInSidePanel.ts

@@ -1,5 +1,6 @@
 export const canOpenObjectInSidePanel = (objectNameSingular: string) =>
   !(
     objectNameSingular === 'workflow' ||
-    objectNameSingular === 'workflowVersion'
+    objectNameSingular === 'workflowVersion' ||
+    objectNameSingular === 'dashboard'
   );

packages/twenty-front/src/modules/page-layout/utils/__tests__/createPendingWidgetPlaceholderLayoutItem.test.ts

@@ -20,7 +20,7 @@ describe('createPendingWidgetPlaceholderLayoutItem', () => {
         h: 6,
         minW: DEFAULT_WIDGET_SIZE.minimum.w,
         minH: DEFAULT_WIDGET_SIZE.minimum.h,
-        static: true,
+        static: false,
       });
     });
 
@@ -51,7 +51,7 @@ describe('createPendingWidgetPlaceholderLayoutItem', () => {
         h: 6,
         minW: DEFAULT_WIDGET_SIZE.minimum.w,
         minH: DEFAULT_WIDGET_SIZE.minimum.h,
-        static: true,
+        static: false,
       });
     });
 
@@ -78,7 +78,7 @@ describe('createPendingWidgetPlaceholderLayoutItem', () => {
       'mobile',
     );
 
-    expect(desktopResult.static).toBe(true);
-    expect(mobileResult.static).toBe(true);
+    expect(desktopResult.static).toBe(false);
+    expect(mobileResult.static).toBe(false);
   });
 });

packages/twenty-front/src/modules/page-layout/utils/createPendingWidgetPlaceholderLayoutItem.ts

@@ -16,5 +16,5 @@ export const createPendingWidgetPlaceholderLayoutItem = (
   h: Math.max(draggedArea.h, DEFAULT_WIDGET_SIZE.default.h),
   minW: DEFAULT_WIDGET_SIZE.minimum.w,
   minH: DEFAULT_WIDGET_SIZE.minimum.h,
-  static: true,
+  static: false,
 });