feat: systemd timery + skripty pro udrzbu serveru

Skripty (4):
- update.sh: apt update + upgrade + restart kdyz nutny + Telegram
- docker-update.sh: docker compose pull + up -d pro vsechny sluzby
- docker-zalohy.sh: tar.zst zaloha data/ adresaru na NAS
- server-report.sh: denni Telegram report (uptime, RAM, disk, Docker)

Systemd (8 - 4x service + 4x timer):
- docker-update: kazdou sobotu 18:00
- docker-zalohy: kazde utery 20:00
- server-report: kazdy den 09:30
- update-rpi: kazdy patek 18:00

Konfigurace:
- conf/telegram.conf.example: sablona pro Telegram credentials
- vsechny skripty ctou z /home/<user>/.telegram.conf (chmod 600)

Poznamka:
- vsechny cesty (/home/mates) a hostname jsou pevne v service souborech
- pro jineho uzivatele uprav User=, WorkingDirectory=, ExecStart=
- zadne IP adresy, tokeny ani PII v gitu

systemd/docker-update.service

@@ -0,0 +1,13 @@
+[Unit]
+Description=Aktualizace Docker kontejneru
+After=network-online.target docker.service
+Wants=network-online.target
+
+[Service]
+Type=oneshot
+User=mates
+WorkingDirectory=/home/mates/skripty/update-docker-script
+ExecStart=/home/mates/skripty/update-docker-script/docker-update.sh
+
+[Install]
+WantedBy=multi-user.target