* feat(eval): show mean score instead of pass/fail in report and viewer
* feat(eval): integrate NopeCHA CAPTCHA solver into eval pipeline
Add CAPTCHA detection and waiting so screenshots capture post-solve state.
Run headed with xvfb on CI since headless breaks extension content scripts.
- Add CaptchaWaiter module (detect reCAPTCHA/hCaptcha/Turnstile, poll until solved)
- Add optional `captcha` config block to EvalConfigSchema
- Wait for CAPTCHA solve before screenshot in single-agent and orchestrator-executor
- Patch NopeCHA manifest with API key before launching workers
- Fix CAPTCHA_EXT_DIR path (was pointing one level too high)
- Remove --incognito (extensions don't run in incognito; fresh user-data-dir isolates)
- CI: install xvfb, run headed via xvfb-run, pass NOPECHA_API_KEY secret
