# Sprint Contract: Rebaseline Audit

## Objective
Audit the existing Phase 1 implementation against the paper-based `docs/MITC4_FORMULATION.md` and produce a concrete rework map before changing solver behavior.

## Required Reading
- /AGENTS.md
- /PROGRESS.md
- /PLAN.md
- /docs/README.md
- /docs/HARNESS_ENGINEERING.md
- /docs/PRD.md
- /docs/ARCHITECTURE.md
- /docs/ADR.md
- /docs/NUMERICAL_CONVENTIONS.md
- /docs/MITC4_FORMULATION.md
- /phases/1-linear-static-mitc4/index.json

## Scope
- Inspect existing C++ implementation and tests only enough to classify what can be retained, rewritten, or deleted in later steps.
- Produce or update planning notes in `PLAN.md` and `PROGRESS.md`.
- If useful, add a short audit artifact under `phases/1-linear-static-mitc4-rebaseline/`.

## Allowed Files
- `PLAN.md`
- `PROGRESS.md`
- `phases/1-linear-static-mitc4-rebaseline/`

## Explicit Non-Goals
- Do not change production C++ behavior.
- Do not rewrite MITC4 formulas.
- Do not unblock stored-reference regression by accepting unsupported Abaqus syntax.

## Tests To Write First
- None. This is a planning and audit sprint.

## Reference Artifacts
- `references/quad_01.inp`
- `references/quad_01_displacements.csv`
- `references/quad_02.inp`
- `references/quad_02_displacements.csv`

## Acceptance Commands
```bash
python scripts/validate_workspace.py
```

## Evaluator Checklist
- The audit identifies conflicts with `docs/MITC4_FORMULATION.md`, especially old averaged-edge basis, `1.0e-6` drilling scale, analytic thickness integration, and direct shear evaluation risks.
- Future work is assigned to later rebaseline steps instead of being fixed here.
- `PLAN.md` and `PROGRESS.md` describe the new state without treating the old P1-01 through P1-14 implementation as authoritative.

## Handoff Requirements
- Record completed audit work in `PROGRESS.md`.
- Keep next implementation tasks in `PLAN.md` or later step files.

## Do Not
- Do not merge this audit with implementation.
- Do not remove old phase history.