Part of #869 (Point-1 C4). Locks the lease broker's ENFORCEMENT half
(launch-runtime.py) and ACTIVATION half (execLeaseGatedRuntime, C1's
LEASE_ACTIVATION_CAPABILITY) as one versioned unit, closing the #828
version-skew gap C1 only made observable.
- New packages/mosaic/framework/tools/lease-broker/activation_version_gate.py:
EXPECTED_ACTIVATION_CAPABILITY (enforcement-owned, mirrors but is
independent from C1's LEASE_ACTIVATION_CAPABILITY), a fail-closed
subprocess probe of the CLI's hidden `mosaic __lease-capability`
command, and an assertion that FAILS LOUD (VersionCouplingError with
an actionable #869 remediation message) on mismatch OR absence —
never a silent pass, never a dead gate.
- launch-runtime.py now runs this assertion first, before any broker
registration, and denies with a dedicated exit code (65) distinct
from its existing usage (64) and registration-failure (1) codes.
- Red-first tests: src/mutator-gate/version_coupling_unittest.py
(module-level match/mismatch/name-mismatch/absent-capability cases,
and seam-level LAUNCHER.main() cases proving the gate runs before
broker registration and never silently passes).
- Existing fail-closed-on-absent-identity lock
(runtime_tools_unittest.py) stays green: matching-capability fakes
were injected into its pre-existing LAUNCHER.main() calls so the new
gate runs alongside, not in place of, identity enforcement.
- mutator-gate.acceptance.spec.ts updated to supply a fake CLI-capability
probe (matching the existing fake-broker/fake-runtime-binary test
doubles already in that suite) everywhere it drives launch-runtime.py
as a real subprocess.
launch.ts and lease-activation-probe.ts are untouched (C2/C5 avoidance,
C1 read-only).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
