RazorWireEndpointRouteBuilderExtensions

Provides extension methods for to map RazorWire endpoints.

Registers a Server-Sent Events (SSE) GET endpoint at the configured streams base path that streams messages for a named channel.

The endpoint enforces channel subscription authorization, streams hub messages as SSE (each line emitted as a `data:` event), sends a 20-second heartbeat comment when idle, and unsubscribes on client disconnect.