Add omarchy-mac-ml meta package for Apple Silicon Macs

Pulls omarchy-mlx, omarchy-mlx-vulkan, omarchy-ane-dkms and
mil-hwx-compiler: MLX on the GPU and Core ML models on the Neural
Engine. Opt-in only; installs through the Install > AI row.

Depends on #745 (omarchy-ane-dkms) and #764 (omarchy-mlx) publishing
first: CI resolves each package against published edge.

pkgbuilds/omarchy-mac-ml/.omarchy/package.json

@@ -0,0 +1 @@
+{ "source": "local", "channels": ["edge"] }