Upgrade to CodeceptJS 4.x with alternative browser configs

[DenysKuchma]

Summary

• CodeceptJS 3.5 → 4.2.1 + refreshed Playwright/Puppeteer/WebdriverIO; removed TestCafe (helper is gone from core in 4.x)
• New configs for alternative no-render browsers: codecept.lightpanda.conf.js, codecept.obscura.conf.js, codecept.moli.conf.js
  (Moli needs codeceptjs > 4.2.1)
• WebDriver config reworked: the wdio plugin was removed in 4.x, replaced with a local chromedriver started via bootstrap hooks
• Test fixes: brittle text assertion (trailing newline in innerText on no-render browsers), removed dead localStorage seeding, tests
  requiring real pointer input (hover, React checkbox toggle) are tagged @full-browser and excluded in alternative-browser configs via
  grep
• README rewritten: comparison table of all supported browsers with their limitations and setup instructions