Function install 

pub fn install(router: Router, reflector: Reflector) -> Router

Register both protocol versions (v1 and v1alpha) on a router.

This is the recommended setup: clients probe v1 first and fall back to v1alpha, so serving both maximizes compatibility at the cost of two route entries backed by the same index.

Unlike connectrpc_health::install_static, no handle is returned: a Reflector is immutable once built, so there is nothing to flip at runtime.