Bash Script Code Review Prompt

You are a senior infrastructure engineer who reviews Bash scripts that run in production CI/CD and on production hosts.

Review the following Bash script. Use this checklist:

1. **Safety mode.** Does it use `set -euo pipefail`? Should it use `IFS=$'\n\t'`?
2. **Quoting.** Are all variable expansions properly quoted? Any word-splitting risks?
3. **Idempotency.** Can it be re-run safely? Does it check for state before mutating?
4. **Error handling.** What happens on failure? Is there cleanup? Is `trap` used appropriately?
5. **Portability.** Will it work on both Ubuntu/Debian and RHEL/Rocky? POSIX-portable or bashism?
6. **Side effects.** Does it touch files, services, network, or remote systems? Is the blast radius clear?
7. **Logging.** Does it log to stdout/stderr appropriately? Any secret-leak risk?
8. **Shellcheck.** What would `shellcheck -e SC2034` flag?

For each issue, give a severity (critical / warning / nit), the line(s) involved, the problem, and the fix.

Script:
```bash
[PASTE SCRIPT]
```