Mills Infrastructure Health Gates

Mills pipeline autonomy now has an explicit infrastructure preflight decision: the operator evaluates the MCP hub, GitLab, vector store, devbox substrate, and other critical dependencies before a pipeline run starts or resumes.

The decision model is fail-closed. Missing evidence, stale evidence, no declared critical dependencies, unknown critical state, or any critical dependency that is not healthy blocks the run and records the reason. Non-critical dependency failures remain visible to the HUD but do not block autonomy by themselves.

Blocked runs are escalated before worker dispatch, with a failure reason that includes the health-gate verdict and any remediation hints. During stability-first planning, remediation and infrastructure-health work is pulled ahead of feature work so the council spends capacity restoring autonomy first.

Operator surfaces:

• health_gates.allowed: whether autonomous Mills pipeline work may proceed.
• health_gates.fail_closed: whether the block came from missing/unknown/stale evidence rather than a known degraded component.
• health_gates.reasons: human-readable block reasons.
• health_gates.remediations: suggested actions to recover the gate.
• HUD monitor, alerting, and fleet projections expose the same verdict.