Demos: DisableExternalEditor (codesandbox, etc.) from menuMeta.json (#33125)

[mpreyskurantov]

Cherry-pick of:

• Demos: DisableExternalEditor (codesandbox, etc.) from menuMeta.json #33125

[Copilot]

Pull request overview

Updates the demos metadata (apps/demos/menuMeta.json) to disable launching certain demos in external editors (CodeSandbox, etc.) via a new DisableExternalEditor flag, likely targeting demos that depend on backend/server infrastructure.

Changes:

• Added DisableExternalEditor: true to multiple demo entries (DataGrid, CardView, Diagram, Scheduler, FileUploader, Localization).
• Adjusted JSON object formatting (commas) to accommodate the new property.

[Copilot]

DisableExternalEditor is added for the DataGrid “Web API Service”, but other demos in the same menuMeta.json that also rely on server-side backend files still don’t have this flag (e.g. “SignalR Service” around lines 88–93, “Remote CRUD Operations” around lines 315–329, “Remote Reordering” around lines 721–735). If the intent is to hide/disable external editors for demos that can’t run standalone, consider applying DisableExternalEditor: true consistently to all such entries (at least those with BackendFiles).

[Copilot]

In the Scheduler “Web API Service” demo, BackendFiles lists "InMemoryAppointmentsDataContext" without the .cs extension, while the same file is referenced as /Models/InMemoryAppointmentsDataContext.cs in MvcAdditionalFiles and most other BackendFiles entries use full filenames. This inconsistency can break tooling that links or copies backend files; consider changing it to InMemoryAppointmentsDataContext.cs.

Suggested change

	"InMemoryAppointmentsDataContext"
	"InMemoryAppointmentsDataContext.cs"

[Copilot]

In the FileUploader section, DisableExternalEditor is added for “Async Upload” and “Validation”, but “Form Upload” (lines ~5234–5246) and “Chunk Upload” (lines ~5267–5278) still declare BackendFiles and do not set DisableExternalEditor. If backend-dependent demos should not be opened in external editors, these entries likely need the flag too for consistent behavior.