Review Docker setup using OWASP Docker Security Cheat Sheet

We should audit our current Dockerfiles, images, and deployment configurations against the OWASP Cheat Sheets to identify and fix potential security gaps. This includes
- [x] [Docker Security Cheat Sheet](https://cheatsheetseries.owasp.org/cheatsheets/Docker_Security_Cheat_Sheet.html)
- [x] [Software Supply Chain Security Cheat Sheet](https://cheatsheetseries.owasp.org/cheatsheets/Software_Supply_Chain_Security_Cheat_Sheet.html)
- [ ] [CI/CD Security](https://cheatsheetseries.owasp.org/cheatsheets/CI_CD_Security_Cheat_Sheet.html)
- [ ] [Secrets Management Cheat Sheet](https://cheatsheetseries.owasp.org/cheatsheets/Secrets_Management_Cheat_Sheet.html)
- [ ] [Best Practices](https://cloudberry.engineering/article/dockerfile-security-best-practices/)
- [ ] [OpenSSF Best Practices](https://best.openssf.org/)

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✅ **Fulfilled**: Requirement is implemented sufficiently

⚠️ **Not Fulfilled**: Requirement is relevant but not yet implemented

⏭️ **Skipped**: Requirement is deliberately not pursued (too much overhead, out of scope, current state is already enough)