Add Replit starter scaffold and bootstrap script for unit-circle-benchmark

[erinepshovel-code]

Motivation

• Provide a zip-safe, runnable Replit starter for the unit-circle embedding benchmark so the project can be quickly scaffolded in a fresh directory or Replit workspace.
• Include a minimal, runnable benchmark skeleton (embedding, transforms, benchmarking, and utilities) and sample data to facilitate quick experimentation and verification.
• Ensure safe behavior when bootstrapping by refusing to overwrite non-empty targets unless explicitly forced.

Description

• Add unit-circle-benchmark/scripts/bootstrap_replit_starter.sh, a script that scaffolds the full project layout, writes templated files, and refuses to run into a non-empty target unless FORCE=1 is set.
• Add a complete starter scaffold under unit-circle-benchmark/ including README.md, requirements.txt, pyproject.toml, .replit, notebooks/, data/ sample JSONL files, outputs/ directories, and a src/ package with config.py, data.py, embed.py, transforms.py, benchmark.py, metrics.py, utils.py, and main.py implementing embedding, transforms (including unit-circle mapping), retrieval/clustering/geometry benchmarks, and I/O helpers.
• Add unit-circle-benchmark/ZIP_SAFE_REPLIT_STARTER.md documenting usage, behavior, created files, safety semantics, and verification commands.

Testing

• Ran the bootstrap script into a temporary directory with bash unit-circle-benchmark/scripts/bootstrap_replit_starter.sh "$tmpdir" and the command completed successfully.
• Verified Python source compilation with python -m compileall src inside the scaffolded directory and it succeeded without syntax errors.

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Codex Task