Enables sortSubcommands on the root program, sessions group, gateway
group, and mission group so all subcommand listings render A-Z. Appends
a Command Groups section via addHelpText to group commands by role
(Runtime, Gateway, Framework, Platform, Runtimes).
Implements CU-04-01, CU-04-02, CU-04-03 from mission cli-unification-20260404.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>