feat(cli): backup system / restore system subcommands

Expose the system-config backup on demand (not just within 'backup all'):

- `libreportal backup system`      -> backupSystemConfig (snapshot the system
  config — settings, WebUI creds, backup-location creds — to all enabled locations)
- `libreportal restore system [loc_idx]` -> backupRestoreSystemConfig (restore the
  latest system snapshot into a staging dir; never overwrites live config)

Distinct from the existing 'restore migrate system' (which restores all *apps*
from another host). Help text updated for both. Routing verified with stubs.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Signed-off-by: librelad <librelad@digitalangels.vip>

scripts/cli/commands/backup/cli_backup_commands.sh

@@ -54,6 +54,9 @@ cliHandleBackupCommands()
         all)
             backupAllApps
             ;;
+        system)
+            backupSystemConfig
+            ;;
         scheduled)
             backupScheduleEnabledApps
             ;;

scripts/cli/commands/backup/cli_backup_header.sh

@@ -19,7 +19,11 @@ cliShowBackupHelp()
     echo "    Delete every backup for an app (skips append-only locations)."
     echo ""
     echo "backup all"
-    echo "    Snapshot every installed app."
+    echo "    Snapshot every installed app (also runs 'backup system')."
+    echo ""
+    echo "backup system"
+    echo "    Snapshot the system config (settings, WebUI creds, backup-location"
+    echo "    creds) to all enabled locations — needed for a self-sufficient restore."
     echo ""
     echo "backup scheduled"
     echo "    Queue a backup for every app with backups enabled (daily cron entry)."

scripts/cli/commands/restore/cli_restore_commands.sh

@@ -36,6 +36,11 @@ cliHandleRestoreCommands()
                     ;;
             esac
             ;;
+        system)
+            # Restore the latest system-config snapshot (settings + creds) into a
+            # staging dir; never overwrites live config. Optional location idx.
+            backupRestoreSystemConfig "$action"
+            ;;
         migrate)
             case "$action" in
                 app)

scripts/cli/commands/restore/cli_restore_header.sh

@@ -9,6 +9,10 @@ cliShowRestoreHelp()
     echo "restore app list <app_name>"
     echo "    List available backups for an app across all enabled locations."
     echo ""
+    echo "restore system [loc_idx]"
+    echo "    Restore the latest system-config snapshot into a staging dir"
+    echo "    (review-then-copy; never overwrites live config). Default: first location."
+    echo ""
     echo "restore migrate app <app_name> <source_host> [loc_idx]"
     echo "    Restore one app's backup taken on another host (cross-host migrate)."
     echo ""