Move the Healthchecks API key out of source code

[ANonABento]

Problem

internal/status/status.go sets the Healthchecks API key directly in code when fetching cluster status.

For a public CLI repo, embedding service credentials in source makes key rotation harder and exposes access to anyone with the repository. Even if the current key is read-only or intentionally scoped, it should be treated as leaked once committed.

Suggested fix

• Revoke/rotate the committed Healthchecks API key.
• Load the key from an environment variable, config file, or backend endpoint instead of hardcoding it in the CLI.
• Make the CLI fail with a clear message when status data requires credentials that are not configured.
• Add a lightweight secret scanning check in CI.

Relevant file

• internal/status/status.go