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, 3 insertions, 3 deletions

diff --git a/packaging/dispatch.install b/packaging/dispatch.install
index 76837f5..75b36cc 100644
--- a/packaging/dispatch.install
+++ b/packaging/dispatch.install
@@ -11,7 +11,7 @@ post_install() {
 	echo "      dispatch-frontend     # static frontend (port 18391 by default)"
 	echo ""
 	echo "    To run as a service, install one of:"
-	echo "      pacman -S dispatch-systemd   # systemd user services"
+	echo "      pacman -S dispatch-systemd   # systemd system services (run as your user)"
 	echo "      pacman -S dispatch-s6        # s6 services (Artix)"
 	echo ""
 	echo "    For the Electron desktop wrapper:"
@@ -22,8 +22,8 @@ post_install() {
 post_upgrade() {
 	echo ""
 	echo "==> Dispatch (base) upgraded."
-	echo "    If you use dispatch-systemd, restart the units:"
-	echo "      systemctl --user restart dispatch-api dispatch-frontend"
+	echo "    If you use dispatch-systemd, restart the units (replace <user>):"
+	echo "      sudo systemctl restart dispatch-api@<user> dispatch-frontend@<user>"
 	echo "    If you use dispatch-s6, restart the services:"
 	echo "      s6-svc -r /run/service/dispatch-api"
 	echo "      s6-svc -r /run/service/dispatch-frontend"