BBOPlace Visualizer

[joyemang33]

Summary

Adds a lightweight BBOPlace placement visualizer:

• tools/bboplace/viz_placement.py
• usage notes in tools/bboplace/README.md

The visualizer renders submitted BBOPlace placements as SVGs by reusing the same Frontier-CS 2.0 task evaluator, BBOPlace MGO legalizer, benchmark data, and MP-HPWL path used for scoring. It supports both direct JSON submissions and Harbor best_submission_payload.json files from real trials.

The tool is intended to run inside the BBOPlace judge/data image, so benchmark data remains outside the agent workspace.

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: developer visualization tool

Testing

• PYTHONPYCACHEPREFIX=/private/tmp/frontier-cs-pycache python3 -m py_compile tools/bboplace/viz_placement.py
• Rendered real Harbor trial payloads through the BBOPlace judge image:
  • bboplace_direct_ispd2005 / adaptec1
  • bboplace_ispd2005 / adaptec1
  • bboplace_iccad2015 / superblue1
• Confirmed rendered HPWL, selected candidate index, score, and overlap values match the corresponding trial metadata.

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

Not applicable; this PR adds a developer visualization tool, not a new problem.