Preflight: score every agent change against incidents you have already solved
Hangar's own dead-ends list is the corpus: each case has a documented cause and a known fix, so the verifier is a deterministic check and not another model. Any change to a profile, a model or a policy has to score no worse than the last one.
Principle honored
Live verification: prove against real state, and never trust a pass that could mean the gate is off. Each case also has a seeded negative run that must fail.
What changes
Runs as a Glidepath pipeline, so it inherits provenance, signing and results archival.
Scored on outcome, blast radius (paths touched vs allowlist), Clearance denials, retries and cost.
Gate lives on the Clearance repo itself: profile, model and policy changes are PRs that must pass Preflight.
Start small
Proposal, not built. Start with two cases (the probe path and the auto-ready bug), because they are one-file fixes with unambiguous verifiers, and add the rest once the harness is trusted.