fix(packaging): convert dispatch-systemd from user units to system template units (User=%i)

The per-user systemd manager ([email protected]) fails to start on WSL
(kernel 6.6.87.2, microsoft/WSL#13186 — 'Failed to spawn executor:
Device or resource busy'), which breaks pacman's
30-systemd-daemon-reload-user.hook on install.

Changes:
- New [email protected] + [email protected] system
  template units with User=%i (run as the named instance user)
- Remove old user-scope dispatch-api.service / dispatch-frontend.service
- Install to /usr/lib/systemd/system/ instead of .../systemd/user/
- Update PKGBUILD, .install hints, and bin/service to use
  sudo systemctl dispatch-api@<user>

1 files changed, 10 insertions, 9 deletions

diff --git a/packaging/dispatch-systemd.install b/packaging/dispatch-systemd.install
index 3bd29be..5ebf261 100644
--- a/packaging/dispatch-systemd.install
+++ b/packaging/dispatch-systemd.install
@@ -1,24 +1,25 @@
 post_install() {
 	echo ""
-	echo "==> Dispatch systemd user units installed."
-	echo "    Enable and start:"
-	echo "      systemctl --user daemon-reload"
-	echo "      systemctl --user enable --now dispatch-api dispatch-frontend"
+	echo "==> Dispatch systemd system unit templates installed."
+	echo "    These run as the user named in the instance (replace <user>)."
+	echo "    Enable and start (e.g. for user 'tradam'):"
+	echo "      sudo systemctl daemon-reload"
+	echo "      sudo systemctl enable --now dispatch-api@<user> dispatch-frontend@<user>"
 	echo ""
 }
 
 post_upgrade() {
 	echo ""
 	echo "==> Dispatch systemd units upgraded."
-	echo "    Reload and restart:"
-	echo "      systemctl --user daemon-reload"
-	echo "      systemctl --user restart dispatch-api dispatch-frontend"
+	echo "    Reload and restart your instances (replace <user>):"
+	echo "      sudo systemctl daemon-reload"
+	echo "      sudo systemctl restart dispatch-api@<user> dispatch-frontend@<user>"
 	echo ""
 }
 
 pre_remove() {
 	echo ""
-	echo "==> Stop dispatch services before removal:"
-	echo "      systemctl --user disable --now dispatch-api dispatch-frontend"
+	echo "==> Stop dispatch services before removal (replace <user>):"
+	echo "      sudo systemctl disable --now dispatch-api@<user> dispatch-frontend@<user>"
 	echo ""
 }