tanin-greet: install greetd config via .install scriptlet (avoid file conflict)

greetd owns /etc/greetd/config.toml, so ship our config to
/usr/share/tanin/greetd/ and activate it from a post_install/post_upgrade
scriptlet (with a one-time backup). Fixes the pacman file conflict.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

packaging/tanin-greet/PKGBUILD

@@ -5,7 +5,7 @@
 # After install:  systemctl enable greetd   (disable any other DM first)
 pkgname=tanin-greet
 pkgver=0.1.0
-pkgrel=1
+pkgrel=2
 pkgdesc="TANINUX login — custom GTK4 greeter for greetd (mirrors the topbar)"
 arch=('any')
 url="https://taninux.kgva.ch"
@@ -13,12 +13,15 @@ license=('GPL-3.0-or-later')
 depends=('greetd' 'cage' 'gtk4' 'python' 'python-gobject'
          'adwaita-icon-theme' 'inter-font')
 optdepends=('tanin-backgrounds: default login wallpaper at /usr/share/backgrounds/tanin/login.jpg')
-backup=('etc/greetd/config.toml' 'etc/greetd/tanin-greet.css')
+backup=('etc/greetd/tanin-greet.css')
+install=tanin-greet.install
 
 package() {
   install -Dm755 "$startdir/tanin-greet"      "$pkgdir/usr/bin/tanin-greet"
   install -Dm644 "$startdir/tanin-greet.css"  "$pkgdir/etc/greetd/tanin-greet.css"
-  install -Dm644 "$startdir/config.toml"      "$pkgdir/etc/greetd/config.toml"
+  # greetd already owns /etc/greetd/config.toml, so we can't package that path.
+  # Ship it as a template; the .install scriptlet activates it (with a backup).
+  install -Dm644 "$startdir/config.toml"      "$pkgdir/usr/share/tanin/greetd/config.toml"
   # The greeter reads its CSS from /etc/greetd by default; no wallpaper is
   # shipped here (provide one at /usr/share/backgrounds/tanin/login.jpg, e.g.
   # via a tanin-backgrounds package — the greeter falls back to a dark scrim).