Crash persists in updateCatalogAndRegistry() on FCP 12.3 despite entitlements fix (#23)

FCP version: 12.3 (Creator Studio)
macOS: 26.5.2

Entitlements verified correct (codesign -d --entitlements - shows all 4 keys including app-sandbox=false explicitly), but crash still occurs identically to the one described in #23.

splicekit.log shows:
[willLaunch] NOTE: Final_Cut_Pro_App.CloudContentCatalog has no ObjC -updateCatalogAndRegistry selector; guarded related ObjC entry points instead

Crash trace (faulting thread):
CloudContentCatalog.updateCatalogAndRegistry()
called from: DemoProjectDownloadHelper.fetchDefaultDemoProject()
Exception: EXC_BREAKPOINT (SIGTRAP)

This suggests updateCatalogAndRegistry() is a Swift-only method without an ObjC-exposed selector in this FCP build, so the existing guard doesn't intercept it.

Start by reproducing the crash in FCP 12.3 and trace DemoProjectDownloadHelper.fetchDefaultDemoProject() into CloudContentCatalog.updateCatalogAndRegistry(). Review the willLaunch selector checks and splicekit.log output; done means the FCP 12.3 path no longer raises EXC_BREAKPOINT when the method has no Objective-C selector.

Written by the indexing model from the issue text.