feat: test framework with bats-core

[nmhjklnm]

Summary

Add automated testing to cac. Currently CI only has ShellCheck + build consistency + JS syntax check. No functional or integration tests.

Scope

Unit tests (bats-core)

• UUID/hostname/MAC generation format validation
• Proxy parsing (_parse_proxy, _auto_detect_proxy)
• Version semver sorting
• Platform detection (_detect_os, _detect_platform)

Integration tests

• cac env create → verify file structure (uuid, stable_id, proxy, .claude/settings.json, etc.)
• cac env check → mock proxy, verify output
• Wrapper injection → verify environment variables are set correctly
• fingerprint-hook.js → verify interception works

E2E tests

• Docker container running full workflow
• Multi-platform CI (macOS + Linux)

Getting started

# Install bats-core
brew install bats-core  # macOS
apt install bats        # Linux

# Run tests
bats tests/

References

• bats-core
• Current CI: .github/workflows/

[nmhjklnm]

Closing as no longer planned.