- MASTER_ONLY_COMMANDS / MASTER_ONLY_GROUPS frozensets enumerate every
command a worker host must not see. Comment block at the declaration
puts the maintenance obligation in front of anyone touching command
registration.
- _gate_commands_by_mode() filters both app.registered_commands (for
@app.command() registrations) and app.registered_groups (for
add_typer sub-apps) so the 'swarm' group disappears along with
'api', 'swarmctl', 'deploy', etc. on agent hosts.
- _require_master_mode() is the belt-and-braces in-function guard,
added to the four highest-risk commands (api, swarmctl, deploy,
teardown). Protects against direct function imports that would
bypass Typer.
- DECNET_DISALLOW_MASTER=false is the escape hatch for hybrid dev
hosts that legitimately play both roles.
tests/test_mode_gating.py exercises help-text listings via subprocess
and the defence-in-depth guard via direct import.