Add commit-pinned release packages omarchy and omarchy-settings

Stable-track counterparts of the -dev packages. Source is pinned to a
single shared upstream commit with a real sha256 (pacman 7 validates
checksums on commit-pinned git sources), versioned per the attached-rcN
convention so vercmp orders rc1 < rc2 < final. Seeded at 4.0.0rc1 from
the quattro tip because no upstream 4.x tag exists yet and the packaging
requires the quattro tree (v3.8.x has no shell/ or etc/).

Both packages stay off the fast ring: RCs publish to edge only; stable
receives finals via bin/repo migrate.

pkgbuilds/omarchy/.omarchy/package.json

@@ -0,0 +1,3 @@
+{
+  "source": "local"
+}