feat: add systemd service + timer, replaces cron watchdog

lem-eval.service: continuous loop worker with LEM_NAMES/LEM_TYPES env
lem-eval-maintain.timer: hourly git pull at :37 (replaces maintain cron)

Usage:
sudo cp systemd/*.service systemd/*.timer /etc/systemd/system/
sudo systemctl daemon-reload
sudo systemctl enable --now lem-eval lem-eval-maintain.timer

Co-Authored-By: Virgil <virgil@lethean.io>

systemd/lem-eval-maintain.service

@@ -0,0 +1,9 @@
+[Unit]
+Description=LEM-Eval git pull (config + tool updates)
+After=network-online.target
+
+[Service]
+Type=oneshot
+User=lemmy
+WorkingDirectory=/home/lemmy/PycharmProjects/LEM-Eval
+ExecStart=/home/lemmy/PycharmProjects/LEM-Eval/lem-eval.sh maintain

systemd/lem-eval-maintain.timer

@@ -0,0 +1,9 @@
+[Unit]
+Description=LEM-Eval maintain timer (hourly git pull)
+
+[Timer]
+OnCalendar=*:37
+Persistent=true
+
+[Install]
+WantedBy=timers.target

systemd/lem-eval.service

@@ -0,0 +1,18 @@
+[Unit]
+Description=LEM-Eval continuous worker
+After=network-online.target ollama.service
+Wants=network-online.target
+
+[Service]
+Type=simple
+User=lemmy
+WorkingDirectory=/home/lemmy/PycharmProjects/LEM-Eval
+Environment=LEM_NAMES=lemer
+Environment=LEM_TYPES=gguf
+Environment=PATH=/home/lemmy/.local/bin:/usr/local/bin:/usr/bin:/bin
+ExecStart=/home/lemmy/PycharmProjects/LEM-Eval/lem-eval.sh loop
+Restart=on-failure
+RestartSec=30
+
+[Install]
+WantedBy=multi-user.target