# Sprint Contract: Core Harness Guardrails

## Objective
Refresh the build, validation, core numeric aliases, DOF enum, and diagnostic guardrails so later MITC4 work has stable test foundations.

## Required Reading
- /AGENTS.md
- /docs/ARCHITECTURE.md
- /docs/ADR.md
- /docs/NUMERICAL_CONVENTIONS.md
- /docs/HARNESS_ENGINEERING.md
- /scripts/validate_workspace.py

## Scope
- Preserve or repair CMake/CTest validation.
- Verify `double` and signed int64 aliases are centralized.
- Verify `UX`, `UY`, `UZ`, `RX`, `RY`, `RZ` mapping to Abaqus DOF `1..6`.
- Improve diagnostics only where needed for later steps.

## Allowed Files
- `CMakeLists.txt`
- `include/`
- `src/`
- `tests/`
- `scripts/validate_workspace.py`
- `PLAN.md`
- `PROGRESS.md`

## Explicit Non-Goals
- Do not implement parser features.
- Do not implement MITC4 stiffness.
- Do not introduce MKL, TBB, or HDF5 APIs into solver core.

## Tests To Write First
- DOF enum and Abaqus DOF number mapping tests.
- Numeric alias compile-time or runtime tests for `double` and int64 paths.
- Validation script smoke test through `python scripts/validate_workspace.py`.

## Reference Artifacts
- None.

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

## Evaluator Checklist
- Core aliases and DOF mapping are not duplicated across modules.
- Diagnostics include enough context for later parser, model, and singular errors.
- Validation remains a real build plus test command.

## Handoff Requirements
- Record changed guardrails and test coverage in `PROGRESS.md`.
- Leave future parser/MITC4 tasks in later step files.

## Do Not
- Do not weaken validation to make tests pass.
- Do not add external library dependencies in this step.