Verify the sign-up email code on Enter - #1536

Summary

On the sign-up email verification step (/login, step verify-email), pressing Enter in the code field did nothing: the input and the "Verify Email" button were not inside a <form>, and the button only had an onClick. Users had to click the button. Reported by Matteo on Cloud after sign-up (/login?redirect=/start-trial).

Changes

• packages/frontend/src/app/login/page.tsx: the code input and the button are now in a <form>. Its onSubmit calls handleVerifyCode only when the code has 6 digits and no request is running, the same rule as the button's disabled. The button is type="submit". The resend link stays outside the form.
• packages/frontend/tests/e2e/neutral-signup-and-billing.spec.ts: new test. Enter with 5 digits does nothing; Enter with 6 digits verifies once and continues to the authorization page.
• app/verify-email/page.tsx has no code input (only links), so nothing to change there.

Same in Cloud and self-hosted: the step is shared by both.

Type

• Bug fix

Testing

• Added/updated unit tests

In packages/frontend:

• npx tsc --noEmit -p tsconfig.json: no errors
• npx eslint src/app/login/page.tsx tests/e2e/neutral-signup-and-billing.spec.ts: 0 errors, 1 existing warning (trialErr unused, line 588, not from this change)
• npx playwright test tests/e2e/neutral-signup-and-billing.spec.ts --workers=1: 7 passed
• The new test without the page.tsx change: 1 failed (the URL never leaves the code screen), so it pins the bug.

Checklist

• My code follows the existing code style
• I have tested my changes locally
• This PR has a descriptive title

Related Issues

None (reported in chat).