Bound batch processing cycle times

[bernalde]

Summary

• Add finite source-derived bounds for batch_processing.cycleTime_log from the production horizon and processing-time constraints.
• Make GAMS-backed benchmark solves use option optcr=1e-6 consistently for direct transformed solves and GDPopt GAMS role solves.
• Record the committed GAMS gap default in benchmark metadata and document it in README/AGENTS.
• Add regression coverage for the new batch-processing bounds, GDP reformulation smoke tests, and benchmark GAMS option generation.

Note: this branch addresses the batch_processing benchmark issue, which is #61. Issue #62 is the separate biofuel issue, so this PR intentionally does not close #62.

Solver Evidence

Direct transformed verification:

/home/bernalde/.pixi/bin/pixi run gdplib-benchmark run \
  --instances batch_processing \
  --strategies gdp.bigm gdp.hull \
  --solver-profile gams-local \
  --gams-solvers dicopt baron gurobi \
  --timelimit 300 \
  --run-id batch_processing_bounds_direct_matrix_20260512 \
  --no-skip-existing --no-summary

Result: 6 rows, 0 failures. BARON/DICOPT objectives were unchanged to numerical tolerance:

• BigM/BARON: 679365.334866, optimal.
• BigM/DICOPT: 679365.323287, optimal.
• Hull/BARON: 679365.334869, optimal.
• Hull/DICOPT: 679365.334507, optimal.

GDPopt GLOA verification:

/home/bernalde/.pixi/bin/pixi run gdplib-benchmark run \
  --instances batch_processing \
  --strategies gdpopt.gloa \
  --solver-profile gams-local \
  --timelimit 300 \
  --run-id batch_processing_gloa_cycle_bounds_20260512 \
  --no-skip-existing --no-summary

Result: 1 row, 0 failures. GLOA now reaches maxTimeLimit instead of failing in Pyomo FBBT. Removing only the new cycleTime_log bounds reproduced the old warning and AssertionError path.

Tests Run

env PYTHONPATH=. /home/bernalde/.pixi/bin/pixi run pytest \
  tests/test_batch_processing.py tests/test_benchmark.py tests/test_release_workflow.py \
  -v --tb=short

Result: 26 passed.

/home/bernalde/.pixi/bin/pixi run test

Result: 288 passed, 1 skipped.

/home/bernalde/.pixi/bin/pixi run lint

Result: passed. The configured exit-zero flake8 report still prints existing repository style debt.

git diff --check

Result: passed.

Notes

The direct targeted command without PYTHONPATH=.:

/home/bernalde/.pixi/bin/pixi run pytest tests/test_batch_processing.py tests/test_benchmark.py tests/test_release_workflow.py -v --tb=short

failed during collection because tests/test_benchmark.py imports the repo-root benchmark.py; the full documented pixi run test path passes.

Closes #61.

[bernalde]

1. Blocking issues: none.

2. Nonblocking issues: none.

3. Questions: none.

4. Tests run and outcomes:

env PYTHONPATH=. /home/bernalde/.pixi/bin/pixi run pytest tests/test_batch_processing.py tests/test_benchmark.py tests/test_release_workflow.py -v --tb=short

Result: 26 passed.

/home/bernalde/.pixi/bin/pixi run test

Result: 288 passed, 1 skipped.

/home/bernalde/.pixi/bin/pixi run lint

Result: passed. The configured exit-zero flake8 report still prints existing repository style debt.

git diff --check origin/main...HEAD

Result: passed.

CI is also green for coverage, lint/style-and-typos, pip installation, and Python 3.10/3.11/3.12.

5. Merge verdict: this PR is merge-ready from my review. I cannot submit an APPROVE review from this account because it is the PR author, so an eligible reviewer still needs to approve.