Build and export native macOS ARM64 (darwin-arm64) OpenStudio-server tarball in CI for OpenStudio-PAT #884

Context

As part of adding the native macOS ARM64 (Apple Silicon) installer in NatLabRockies/OpenStudio-PAT#311, we investigated the OpenStudio-server-5873e0d21d-darwin-arm64.tar.gz artifact currently uploaded to s3://openstudio-resources/pat-dependencies3/.

Problems with Current OpenStudio-server-5873e0d21d-darwin-arm64.tar.gz Artifact

The existing darwin-arm64 tarball on S3 appears to have been manually packaged from a local rbenv environment rather than built by CI against PAT's portable static Conan Ruby:

1. Outdated commit/version: Packaged from 5873e0d21d (3.10.0) instead of d6e89510a0 (3.11.0).
2. Hardcoded local rbenv libruby link: All 12 compiled .bundle native extensions link against /Users/achapin/.rbenv/versions/3.2.2/lib/libruby.3.2.dylib instead of being built with -Wl,-undefined,dynamic_lookup against PAT's static Conan Ruby (ruby-3.2.2-darwin-arm64.tar.gz).
3. Mismatched gem extension directory: Native extensions are placed under gems/ruby/3.2.0/extensions/arm64-darwin-24/3.2.0 instead of arm64-darwin-23/3.2.0-static (which PAT's bundled static Ruby expects).
4. Archive structure & pollution:
   • Uses ./ path prefixes instead of a top-level OpenStudio-server/ directory.
   • Contains a nested 88 MB OpenStudio-server-5873e0d21d-darwin-arm64.tar.gz inside itself alongside .git/ and macOS ._* AppleDouble resource fork files.

Required Changes

1. ci/github-actions/setup.sh:
   • Detect architecture via uname -m on macOS runners.
   • When uname -m is arm64:
     • Download https://openstudio-resources.s3.amazonaws.com/pat-dependencies3/ruby-3.2.2-darwin-arm64.tar.gz
     • Download https://fastdl.mongodb.org/osx/mongodb-macos-arm64-8.0.12.tgz (or aarch64)
     • Download OpenStudio-${OPENSTUDIO_VERSION}${OPENSTUDIO_VERSION_EXT}+${OPENSTUDIO_VERSION_SHA}-Darwin-arm64.tar.gz
2. bin/openstudio_meta (InstallGems export) & ci/github-actions/export_build_osx.sh:
   • Set platform = 'darwin-arm64' when RUBY_PLATFORM =~ /arm64/ so the exported filename is OpenStudio-server-<sha>-darwin-arm64.tar.gz.
   • Run tar with COPYFILE_DISABLE=1 when creating the archive so ._* AppleDouble files are not included, with a clean top-level OpenStudio-server/ prefix and no nested tarball or .git directory.
3. CI Workflow (.github/workflows/openstudio-server-tests.yml / build-installers.yml) & S3 Upload:
   • Add a macos-15 (ARM64) build/export job alongside macos-15-intel (x86_64).
   • Upload the resulting OpenStudio-server-<sha>-darwin-arm64.tar.gz to s3://openstudio-resources/pat-dependencies3/ and update manifest.json in Create macOS arm installer OpenStudio-PAT#311.