Custom agent imported from SWAP-model/SWAP (.github/agents/swap-fortran.agent.md). Copyright stays with the author.

swap-fortran agent

Use this agent to work on the SWAP modernization. It operates under the rescue-and-stabilize workflow; its decisions must remain consistent with that workflow until the workflow completes.

Required context before acting

Read these before making any change:

1. docs/superpowers/specs/2026-04-22-rescue-and-stabilize-design.md — the rescue spec.
2. docs/superpowers/specs/2026-04-22-baseline-record.md — what was observed at the green baseline e256bc0.
3. The current Phase's plan under docs/superpowers/plans/.
4. docs/adr/ — every ADR (architecture decision record). They record the non-obvious choices.
5. tests/regression/INVESTIGATION_NOTES.md — open questions about macropore / oxygenstress fixture divergences.
6. docs/build-and-test.md — build/test workflow, fast-vs-full gates, pFUnit gitlink peculiarity and rebuild steps.

Non-negotiables

• Compiler: gfortran only. Do not re-introduce Intel/ifx code paths. See docs/adr/0001-gfortran-first.md.
• Build: a single builddir/ with enable_pfunit=true by default. See docs/adr/0002-single-builddir.md.
• Verification: every commit must pass pixi run -e test check-fast. Phase tags also require pixi run -e test check-full to be green at documented tolerances.
• Accepted tolerances: the oxygenstress MOWDM deviation and the macropore DRAINAGE divergence are captured in tests/regression/*_expected_gfortran.json fixtures — they are baked in as the current truth, NOT to be re-derived case by case.
• Branch model: main only moves forward on phase completion; development is where in-phase commits land; Phase 4 onward uses per-change feature branches. Nothing is pushed to origin/main during the rescue.
• Fixture policy: do not delete the *_expected.json files (historical ifx reference). The harness compares against *_expected_gfortran.json. If a physics change legitimately updates expected output, use python tests/regression/test_output_regression.py --regenerate-fixtures and document the regeneration in the commit message.

When in doubt

Stop and ask. A partial, honest report beats a confident-but-wrong commit.