Two bugs prevented form submission entirely:
1. `challengeurl` attribute was renamed to `challenge` in altcha v3 — the
widget silently ignored the old name so it never fetched a challenge.
2. `altchaWidget.value` is not an exposed property on the v3 custom element;
read the solved payload from the hidden `<input name="altcha">` the widget
renders in light DOM instead.
Also clears the err-altcha error message at the start of each submit attempt
so it doesn't linger after the user completes verification and retries.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
chris
01cad11472