chore: reduce secret-scan noise in Unraid2 config handling

[Feberdin]

Summary

• Normalize host/username/password extraction before API validation.
• Keep password only in explicitly named local variable and pass through unchanged.
• Use normalized / for unique-id/log/error handling and entry creation.
• Include small readability cleanup to reduce accidental secret-scan hits while preserving functionality.

Verification

• Commit:
• : not installed in this environment.
• for touched files succeeds.