docs(claude): update CLAUDE.md with comprehensive codebase documentation

Completely revamp CLAUDE.md to provide AI assistants with detailed
codebase understanding:

Added Sections:
- Project Overview with version and tech stack
- Detailed project structure tree with file descriptions
- Comprehensive test suite organization and markers guide
- Docker and Kubernetes deployment documentation
- Dependencies breakdown (production and dev)
- Architecture & Key Decisions section covering:
  - Evolution timeline (v1.0.x → v1.2.x)
  - StateManager architecture and migration patterns
  - View synchronization strategy evolution
  - Game logic patterns and win conditions
  - UI/UX design decisions and color schemes
  - Testing strategy evolution and test pyramid
  - File organization principles
  - Known issues and gotchas
  - Performance considerations
- Quick Reference Cheat Sheet with:
  - Most common commands
  - Project locations map
  - Common tasks and solutions
  - Key concepts to remember
  - Troubleshooting guide
  - Version history highlights
  - Resource links

Enhanced Sections:
- Build Commands with test category examples
- Test Suite Organization with 165+ test breakdown
- CI Test Execution with exclusion rationale
- Writing New Tests with marker examples
- Test Coverage Goals with specific targets
- StateManager usage consolidated into quick reference

Documentation now provides:
- Clear entry points (app.py vs main.py)
- Understanding of modular vs legacy architecture
- State persistence migration guide
- Timer-based sync vs deprecated ui.broadcast()
- Test marker system for selective execution
- CI optimization strategy (139 tests in ~7s)
- Docker and Helm deployment workflows
- Complete troubleshooting scenarios

This comprehensive update enables AI assistants to:
- Understand project evolution and architectural decisions
- Navigate codebase effectively with file location guide
- Write tests with appropriate markers
- Debug common issues with troubleshooting guide
- Follow established patterns and conventions
- Deploy using Docker/Kubernetes

References version 1.2.1 state as of 2025-11-15.

Author: claude