Go CLI Design

A good CLI is a well-behaved Unix citizen: flags before magic, stdout for data, stderr for diagnostics, exit codes that scripts can trust, and Ctrl+C that actually stops it.

Detailed reference material, loaded on demand:

• references/testing-and-versioning.md — exit-code mapping in main, golden-file and testscript tests, version from build info, completions.

Read a reference file only when the summary below is not enough.

1. Structure: Testable main