Reviewed plans and state ownership

This required 22–32-hour integrated package strengthens the original plan/concurrency/recovery labs: lessons/predictions 5–7 hours, model and original-tool evidence 10–15, assessment/repair 7–10. Reuse original artifacts; these author estimates await semester reconciliation and learner timing pilots.

Prerequisite bridge

Bring Semester 06 transaction/concurrency reasoning, Semester 08 migration generations and Semester 09 inventory evidence. Distinguish resource identity, state lineage, state serial, source revision and lock acquisition. Review these separately before touching state recovery.

Sequence

1. Reviewed artifact identity.
2. Lock ownership and freshness.
3. Partial-apply reconciliation.
4. Implement state-plan-contracts.zip with Python 3 standard library. Run python3 -B check.py starter before reference calibration.
5. Complete IA1–IA6 and retain the original pipeline, drift/import and module-upgrade exercises.

The lab tests 50 contention/value histories plus invalid and stale-token cases. It is an atomic, sequential in-memory model, not Terraform or a remote backend. Each successful model apply increments serial even for an unchanged value; real no-op state behavior can differ. Model plans are trusted inputs, not authenticated artifacts. External drift, crash persistence and partial provider effects are deliberately outside the model.

No cloud account or spending is needed for the model. If Terraform is unavailable, complete predictions and the model, record the tool gap, and leave actual-tool gates pending. Do not substitute a mock trace for a real plan, import or module-upgrade run.