Helper function to create a broadcast event schema.
Broadcast events are fire-and-forget but delivered to ALL listeners, not just the first one.
Type-branded to ensure compile-time category validation.
v9: Uses BSBType for cross-language support. Type inference via InferBSBType.
Helper function to create a broadcast event schema. Broadcast events are fire-and-forget but delivered to ALL listeners, not just the first one. Type-branded to ensure compile-time category validation. v9: Uses BSBType for cross-language support. Type inference via InferBSBType.