Adds two direct-placement BBOPlace Frontier-CS 2.0 tasks

[joyemang33]

Summary

Adds two direct-placement BBOPlace Frontier-CS 2.0 tasks:

• bboplace_direct_ispd2005
• bboplace_direct_iccad2015

Unlike the suite-style BBOPlace tasks, these variants ask the agent to directly produce one JSON placement for one fixed design:

• ISPD2005 direct: adaptec1
• ICCAD2015 direct: superblue1

Agents may write Python scripts, shell scripts, search loops, local parsers, or other helper programs during the trial, but the final graded artifact is /app/solution.json. The judge uses the same CPU-only BBOPlace MGO MP-HPWL evaluation path and relaxed MGO baselines as the suite tasks.

This also extends the Frontier-CS 2.0 adapter reference-solution handling so file submissions with non-.py paths, such as /app/solution.json, can still generate valid Harbor reference artifacts without affecting directory-style tasks like Vector DB ANN.

Please read CONTRIBUTING.md before submitting.

Type of Change

• New research problem
• New algorithmic problem
• New Frontier-CS 2.0 problem
• Bug fix
• Documentation update
• Other:

Testing

• PYTHONPYCACHEPREFIX=/private/tmp/frontier-cs-pycache python3 -m py_compile 2.0/problems/bboplace_direct_ispd2005/evaluator.py 2.0/problems/bboplace_direct_iccad2015/evaluator.py adapters/frontier-cs-2.0/src/frontier_cs_2_0/adapter.py
• Generated all four BBOPlace Harbor tasks:
  • bboplace_ispd2005
  • bboplace_iccad2015
  • bboplace_direct_ispd2005
  • bboplace_direct_iccad2015
• python3 tools/bboplace/check_generated_tasks.py /private/tmp/frontier-cs-bboplace-generated
• Generated vector_db_ann_relaxed as a non-BBOPlace adapter smoke test to confirm directory submissions were unaffected.
• Ran judge-image smoke tests for both direct tasks:
  • bboplace_direct_ispd2005 on adaptec1
  • bboplace_direct_iccad2015 on superblue1
• Ran a real Harbor Codex trial for bboplace_direct_ispd2005 with local Codex auth injection. The agent submitted multiple valid JSON artifacts and the judge returned metrics correctly; all valid placements scored 0 because their HPWL remained above the relaxed baseline.

Checklist

• Code follows the project structure and conventions
• Self-review completed
• Documentation updated (if applicable)

CI Validation (for new problems)

When adding new problems, CI will automatically validate that your reference solution achieves score > 0.

• Algorithmic problems: Include reference.cpp in your problem directory
• Research problems: Include reference.py (or reference.cpp if language: cpp in config.yaml)
• 2.0 problems: Include reference.py unless the problem config declares another language

These direct JSON tasks include reference.json because the configured submission path is /app/solution.json.