- UseJsonExceptionHandler now maps InvalidOperationException to 400 (was 500),
so upstream business-rule rejections reach the browser as actionable messages.
- CvMatcherController forwards Refit 4xx bodies from cv-matcher-api instead
of swallowing them in a generic 502.
- ErrorResponse.Score removed; CaptchaController puts the score in Detail.
- Frontend extractApiError helper reads the server Error/error/title field for
4xx responses and falls back to a generic i18n string for 5xx / missing body.
- All four failure handlers (CV upload, CV match, contact form, subscribe form)
updated to use extractApiError with the correct rate-limit i18n key.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>