docs: Add comprehensive docstrings to Go files

[google-labs-jules]

This commit adds comprehensive docstrings to all Go files in the root of the repository, achieving 100% documentation coverage. Examples have been included where appropriate to improve clarity.

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PR created automatically by Jules for task 10021439630938846058 started by @Snider

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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