[Zaldaryon]

Summary

Completes the macOS prerequisite and source-built installer path for #158. This follows the task's later requirement to work without Homebrew: missing tools receive official manual install instructions and architecture-specific links. The installer does not run brew install, install Homebrew, or change persistent shell configuration.

The process and child tools now search the macOS SDK, Command Line Tools, Homebrew prefix, and .NET tool directories. The macOS prerequisite list separates required and optional tools. Apple's Bash 3.2 and BSD utilities work in the bootstrap and patch-check scripts. The installer writes a native launcher and safe .app shortcuts, and preserves unrelated existing application directories.

Validation

• dotnet test Optimum.Installer.slnf -c Release --nologo: 349 passed, 0 failed, 0 skipped.
• Local equivalents of all six Shell scripts CI checks passed.
• bash -n and git diff --check passed.
• On macOS Tahoe 26.7.1 x86-64, prerequisite scanning, bootstrap, donor preparation, patch validation, packaging, and the full GUI installation completed. Launch Services registered the generated app.
• The Reims vGPU cannot currently render the game. A standalone OpenGL draw reproduces a Metal command-buffer GPU hang after context creation. This is a VM graphics limitation, not a successful game runtime test.