feat: add SECURITY.md - #1

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

The following taps are not trusted: aws/tap Homebrew is currently ignoring formulae, casks and commands from these taps because tap trust is required. Untap them with: brew untap aws/tap Trust specific formulae, casks and commands with: brew trust --formula <user>/<tap>/<formula> brew trust --cask <user>/<tap>/<cask> brew trust --command <user>/<tap>/<command> Whole-tap trust is broader and includes all current and future formulae, casks and commands from the listed taps. Trust whole taps with: brew trust aws/tap To disable trust checks: export HOMEBREW_NO_REQUIRE_TAP_TRUST=1 This is not recommended and will be removed in a later release. For more information, see: https://docs.brew.sh/Tap-Trust