docs: improve Claude rules based on eval results

[KRRT7]

Summary

• Strengthened docstring, verification, tmp_path, and .resolve() rules based on eval runs comparing with-rules vs without-rules behavior
• Expanded git commit/PR conventions and bug fix workflow instructions
• Added type annotation and verification rules that were missing

Eval findings that drove changes

• Docstrings: Both with/without rules added docstrings — stronger phrasing needed
• tmp_path: With-rules agent copied old tempfile.mkdtemp() from existing code — explicitly banned alternatives
• .resolve(): Never followed — added concrete example
• prek: Baseline ran ruff/mypy separately — clarified prek is the single command

[claude]

Claude finished @KRRT7's task in 15s —— View job

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No substantive code changes to review.