moa, fallback, worktree, browser, secrets, egress, migrate, whatsapp-cloud,
checkpoints, bundles, curator, pets, journey, computer-use, sessions and
completion each become a build_<group>_parser() builder. Closure handlers
that only closed over their own parser moved verbatim; sessions/completion
take the handler by injection. --help/usage/defaults byte-identical for all
399 parsers in the tree (in-process dump before/after).
Teknium