add retry on failure for saints.service

If the Mastodon post fails (e.g. instance temporarily down), systemd
will retry up to 5 times at 15-minute intervals over a 12-hour window
before triggering the OnFailure notification.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

saints/saints.service

@@ -9,9 +9,13 @@
 [Unit]
 Description=Run get_saint_of_the_day.py (profile stats updater)
 OnFailure=notify-gitea-failure@%n.service
+StartLimitBurst=5
+StartLimitIntervalSec=43200
 
 [Service]
 Type=oneshot
+Restart=on-failure
+RestartSec=900
 EnvironmentFile=%h/.config/saints.env
 ExecStartPre=/usr/bin/nm-online -q
 ExecStartPre=/bin/bash -c 'for i in {1..600}; do getent hosts tildegit.org && exit 0; sleep 1; done; exit 1'