BackendListProvider

Platform-neutral source of the proxy's currently-registered backend servers. Velocity and Bungee implementations expose the proxy's server list (from velocity.toml / config.yml) as a list of Backend records that NetworkSync can hit for backend Bedrock assets.

HTTP port discovery: backends announce the ResourcePackManager HTTP port they actually bound to the shared remote endpoint registry. The proxy matches that announcement to this list and fetches http://<host>:<announcedPort>/bedrock.zip. If an announcement is not available yet, the proxy falls back to mcPort() + networkHttpOffset for startup compatibility.