docs: Add complete architecture documentation with C4 diagrams
- System Context diagram (C4 Level 1)
- Container diagram (C4 Level 2)
- Flask component diagram (C4 Level 3)
- Deployment architecture with NPM proxy
- Database schema (PostgreSQL)
- External integrations (Gemini AI, Brave Search, PageSpeed)
- Network topology (INPI infrastructure)
- Security architecture
- API endpoints reference
- Troubleshooting guide
- Data flow diagrams (auth, search, AI chat, SEO audit, news monitoring)
All diagrams use Mermaid.js and render automatically on GitHub.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Maciej Pienczyn
fa4fb92390