Fix Borg preflight freshness dump path

ops/borg-ui/scripts/pre-borg.sh

@@ -10,6 +10,18 @@ NTFY_SCRIPT="${NTFY_SCRIPT:-$REPO_ROOT/ops/restore-tests/send-ntfy.sh}"
 NTFY_TOPIC="${NTFY_TOPIC:-homelab-alerts}"
 ALLOW_POSTURE_WARNING="${ALLOW_POSTURE_WARNING:-1}"
 
+case "${DUMP_ROOT:-}" in
+  */latest)
+    FRESHNESS_DUMP_ROOT="${FRESHNESS_DUMP_ROOT:-$DUMP_ROOT}"
+    ;;
+  "")
+    FRESHNESS_DUMP_ROOT="${FRESHNESS_DUMP_ROOT:-/mnt/user/backups/borg/dumps/latest}"
+    ;;
+  *)
+    FRESHNESS_DUMP_ROOT="${FRESHNESS_DUMP_ROOT:-$DUMP_ROOT/latest}"
+    ;;
+esac
+
 notify_failure() {
   local step="$1"
   local message="$2"
@@ -45,6 +57,6 @@ else
   fi
 fi
 run_step "pre-backup-dumps" "$PRE_BACKUP_DUMPS"
-run_step "restore-freshness" "$FRESHNESS_CHECK"
+run_step "restore-freshness" env DUMP_ROOT="$FRESHNESS_DUMP_ROOT" "$FRESHNESS_CHECK"
 
 echo "[pre-borg] All pre-flight checks passed"