NOTE
Netty Server Startup: Creating the Server Channel
First server-startup phase: Bootstrap configuration produces a concrete listening-channel instance.
This is a historical learning note and may contain outdated or incomplete understanding.
Starting a Netty server begins from ServerBootstrap configuration and eventually creates the configured server-channel implementation through a channel factory/type.
The new channel contains transport, configuration, pipeline, and lifecycle state but is not yet a listening endpoint. Initialization, registration, and bind occur in subsequent phases.
Exact creation helpers/constructors are version-specific.