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Description
Describe the problem
It would be nice if I could set App.PageData different for each layout, and then the pages inside the layout should be forced to extend that interface.
For example, a website may have a "general" layout and an "administrator" layout. I want to set the title on the layout based on the current page data. But inside the admin portal, it is different.
Describe the proposed solution
Have a way to declare the interface inside layout.svelte instead of app.d.ts
Alternatives considered
No response
Importance
nice to have
Additional Information
Related to #11779 because if I can't enforce it, it's not very useful.