The example passed title, Component, and onPress straight to
addComposerPill and treated its return value as a remover function, so it
failed to typecheck against @getpaseo/plugin. It also followed agents with
agents.subscribe, a local listener that never delivers agents that exist
before the plugin loads. The example now uses the button descriptor and an
owned list subscription, like the plugin reference and local-plugin
example, and a test typechecks it against the SDK.
Closes#5517
Co-authored-by: paseo-bot[bot] <266920839+paseo-bot[bot]@users.noreply.github.com>
