Cannot register a custom WP-CLI command

You are trying to add a subcommand to a non-existing command posts according to the error message.

Modify it to a single word command like posts-scan or add a subcommand to an existing command, like post.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)