refactor: replace mapfile with compatible loop for reading manifest entries

setup/cleanup.sh

@@ -215,8 +215,11 @@ for host in "${HOSTS[@]}"; do
 
   ssh_key=$(host_to_ssh_key "$host")
 
-  # Read entries into array, then reverse
-  mapfile -t entries < <(manifest_entries "$host")
+  # Read entries into array, then reverse (bash 3.2 compatible — no mapfile)
+  entries=()
+  while IFS= read -r _entry_line; do
+    entries+=("$_entry_line")
+  done < <(manifest_entries "$host")
 
   if [[ ${#entries[@]} -eq 0 ]]; then
     log_info "No entries in ${host} manifest — skipping"