Merge feature/claude-mece-merge into main

feat: Complete MECE merge implementation with adaptive execution and rate limiting

chore: remove dead code and obsolete configuration

docs: add architectural review and migration documentation

docs: update README with project overview and setup

docs: update CLAUDE.md with comprehensive development guide

docs: reorganize architecture documentation

test: add integration and performance test suites

test: update unit tests for refactored modules

refactor: implement 4-phase orchestration in index.js

refactor: update core modules to class exports for DI

feat: add synthesis layer with decision matrix

feat: add sub-agent architecture for specialized analysis

feat: add state management for resilient reviews

feat: add feature flags system for gradual rollout