Add quickshell 0.3.2 built from upstream releases (#855)

Tracks tagged releases from the quickshell-mirror GitHub repository
through an upstream watch, so new versions arrive via sync-upstream.
The recipe follows Arch's extra/quickshell, builds for x86_64 and
aarch64, ships the Qt compatibility check hook, and rebuilds on Qt
updates like quickshell-git. It conflicts with quickshell-git.

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

pkgbuilds/quickshell/quickshell-check.hook

@@ -0,0 +1,10 @@
+[Trigger]
+Operation = Upgrade
+Operation = Install
+Type = Package
+Target = qt6-base
+Target = qt6-wayland
+[Action]
+Description = Querying Quickshell compatibility after Qt6 update...
+When = PostTransaction
+Exec = /usr/bin/quickshell --private-check-compat