chore: track AUR package files (PKGBUILD, .SRCINFO)

The aur/ directory was entirely gitignored, preventing PKGBUILD and
.SRCINFO files from being tracked. Fix .gitignore to only ignore
build artifacts and nested .git dirs, matching the owlry-plugins
repo convention.

.gitignore

@@ -4,6 +4,7 @@ CLAUDE.md
 media.md
 
 # AUR packages (each is its own git repo for aur.archlinux.org)
+# Track PKGBUILD and .SRCINFO, ignore build artifacts and sub-repo .git
 aur/*/.git/
 aur/*/pkg/
 aur/*/src/
@@ -11,6 +12,3 @@ aur/*/*.tar.zst
 aur/*/*.tar.gz
 aur/*/*.tar.xz
 aur/*/*.pkg.tar.*
-# Keep PKGBUILD and .SRCINFO tracked
-.SRCINFO
-aur/