This repository is a public portfolio archive. Never commit Wi-Fi passwords, Firebase database secrets, API keys, or private endpoints.

For CUBE_ver.2, CUBE_ver.3, and CUBE_ver.4:

1. Copy secrets.example.h to secrets.h in the same directory.
2. Replace the placeholders with local development credentials.
3. Keep secrets.h untracked; it is covered by .gitignore.

If a credential is committed accidentally, deleting it in a later commit is not enough. Revoke or rotate it first, then remove it from the entire Git history before publishing.

Do not open a public issue containing a secret. Contact the repository owner privately through the GitHub profile instead.