Problem: After a failed login attempt, the user had to re-run
`:CP <platform> login` manually. Cancel messages lacked context, and
credential prompts in `submit.lua` used raw platform IDs instead of
display names.
Solution: `prompt_and_login` now recurses after failure so the user is
re-prompted until they cancel or succeed. `submit.lua` extracts the
scraper call into `do_submit` and re-prompts via `prompt_credentials` on
`bad_credentials`. Username prompts show `<Esc> to cancel`, and cancel
messages include the platform display name.
Barrett Ruth
e3c81e895a
