Resolves #48448. These should help with reviewing the XAR and BOM implementations: - https://claude.ai/code/artifact/60a78c1d-2fc9-45da-9471-1517fe77adb4. - https://claude.ai/code/artifact/1c759a32-02f7-4a41-8611-04d7358367d7. The darwin only tests (bom_darwin_test.go) have been executed on my workstation. Goal is to make sure to run the tests on macOS Github runners in https://github.com/fleetdm/fleet/issues/33371. - [X] Changes file added for user-visible changes in `changes/`, `orbit/changes/` or `ee/fleetd-chrome/changes`. ## Testing - [x] QA'd all new/changed functionality manually ## fleetd/orbit/Fleet Desktop - [x] Verified compatibility with the latest released version of Fleet (see [Must rule](https://github.com/fleetdm/fleet/blob/main/docs/Contributing/workflows/fleetd-development-and-release-strategy.md)) - [x] Verified auto-update works from the released version of component to the new version (see [tools/tuf/test](../tools/tuf/test/README.md)) <!-- This is an auto-generated comment: release notes by coderabbit.ai --> ## Summary by CodeRabbit * **New Features** * macOS package builds now use an internal, built-in implementation instead of external packaging tools. * `.pkg` installer creation no longer depends on Docker for macOS packaging. * **Bug Fixes** * Improved packaging reliability by reducing platform-specific build steps. * Packaging test coverage was streamlined to better match the supported build environment. <!-- end of auto-generated comment: release notes by coderabbit.ai -->