docs: rewrite README in Nick-style — bilingual EN/RU, mermaid arch, hero-table

- README.md (English-primary): badges row + bilingual switcher + bold lead +
  'Why this exists' + 'How it works' mermaid diagram + phase table +
  'What you actually get' file tree + 3-min Quick Start + 'What gets tested
  out of the box' + severity model + CLI reference + status section
- README.ru.md: full Russian translation of the same structure
- Repo topics: 20 tags added (claude-code, claude-skill, playwright, axe-core,
  accessibility, wcag, supabase, nextjs, image-budget, mcp, mcp-servers, etc.)
  for awesome-* discoverability

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: CreatmanCEO