docs: Update cron schedules to match actual configuration

- Correct permanent ban script cron schedule: 2:00 AM daily (not every 6 hours)
- Correct geoip-shell update cron schedule: 4:08 AM daily (not 4:18 AM)
- Add geoip-shell persistence cron job that runs on reboot

docs/network-security.md

@@ -489,7 +489,7 @@ THRESHOLD=4  # Ban after 4 fail2ban bans
 - **Iptables Rules:** `/etc/iptables/iptables.rules`
 
 #### Cron Schedule
-- **Frequency:** Every 6 hours (`0 */6 * * *`)
+- **Frequency:** Daily at 2:00 AM (`0 2 * * *`)
 - **User:** root
 - **Command:** `/home/hoborg/homelab/scripts/permanent-ban-repeat-offenders.sh`