On startup BanGUI now verifies that the four fail2ban jail config files
required by its two custom jails (manual-Jail and blocklist-import) are
present in `$fail2ban_config_dir/jail.d`. Any missing file is created
with the correct default content; existing files are never overwritten.
Files managed:
- manual-Jail.conf (enabled=false template)
- manual-Jail.local (enabled=true override)
- blocklist-import.conf (enabled=false template)
- blocklist-import.local (enabled=true override)
The check runs in the lifespan hook immediately after logging is
configured, before the database is opened.