Implement detailed install/uninstall tests with bats

[nirs]

Summary

The current install workflow provides basic verification but lacks detailed permission/ownership checks and can only run on GitHub.

Goals

1. Comprehensive testing:

   • Verify file permissions and ownership (root:wheel for install dir, _vmnetbroker for log dir)
   • Verify system user/group creation with correct attributes
   • Verify service registration and state
   • Verify all files are removed on uninstall

2. Local testing:

   • Implement as bats tests instead of inline GitHub Actions YAML
   • Allow developers to run install tests locally
   • GitHub workflow calls the bats tests

Current gaps

• Testing install from local tar duplicate workflow tests
• Installing from local script not tested with latest release
• Wrong permissions pass (only visible in logs, no assertion)
• Tests only run on GitHub, not locally
• Duplicated verification logic between workflow and scripts

Implementation

• Create test/install.bats with comprehensive checks
• Update workflow to call bats tests
• Add make test-install target (requires sudo)?

Example bad changes not detected by the current test

• Try bad install change #81