fix: stop marking newly created apps as draft in playground

The  atom returned  when
 was null. For ephemeral/newly-created entities (no server
baseline),  always exists, so every new app was falsely
marked as dirty — showing an unexpected "draft" badge on the node
name tag in SingleLayout.

Change the fallback to : an entity with no server
baseline is clean until the user makes actual edits.

Fixes #4556

Author: GanJiaKouN16

web/packages/agenta-entities/src/workflow/state/store.ts

@@ -1623,7 +1623,9 @@ export const workflowIsDirtyAtomFamily = atomFamily((workflowId: string) =>
         const serverData = get(workflowServerDataSelectorFamily(workflowId))
 
         if (!serverData) {
-            return !!entityData
+            // No server baseline (ephemeral / newly created entity) —
+            // treat as clean until the user makes actual edits.
+            return false
         }
         if (!entityData) return false