Install CLI completion and man page assets

[konojunya]

Summary

• update the formula to the verified Stack CLI v0.4.0 release
• install the archive-provided bash, zsh, and fish completions plus stack.1 through Homebrew helpers
• compare every installed asset with fresh generator output in the formula and lifecycle tests
• derive release versions from tracked metadata so verification and upgrade tests stay synchronized

Verification

• scripts/test-formula-source.sh
• bash -n scripts/*.sh
• ruby -c scripts/render-stack-formula.rb
• ruby -c Formula/stack.rb
• generated formula diff check
• brew style stack-sh/tap
• brew audit --strict stack-sh/tap/stack
• local ARM64 macOS install, formula test, revision upgrade, uninstall, managed-file removal, and user-data preservation lifecycle