PeerLauncher.disabledModels() reported an empty set both when no
models: block exists and when a block exists with nothing off, so
fleet_profiles/GET /profiles and the startup log could not tell an
inert gate from an armed one reporting zero. Add
PeerLauncher.ModelGateState (configured + off), a modelGateState()
default method disabledModels() now delegates to, and a
CompositePeerLauncher override that reads models0() once and
distinguishes the null-supplier case (no models: block) from a real,
config-supplied block via identity against the NO_MODELS_CONFIGURED
sentinel — reusing the exact accessor the spawn gate itself reads, per
the fleetd #404 lesson.
Wires the state into a new startup log line (Fleetd.modelGateCoverageLine)
and a new modelGateArmed field in FleetMcp.profilesView, reported
unconditionally alongside the existing modelsOff set.
Dai Ha