docs: add comprehensive git commit summary and deployment guide

Add GIT_COMMIT_SUMMARY.md documenting:
- Complete commit history (15 commits)
- Code changes statistics (145+ files, ~50,000 lines)
- Test coverage metrics (231 tests, 87.5% pass rate)
- Quality improvements (60% failure reduction)
- Deployment readiness checklist
- CI/CD pipeline status
- Migration guide for team members
- Next steps and post-merge tasks

This document serves as:
- Comprehensive change log
- Deployment reference
- Team migration guide
- Quality metrics baseline
- CI/CD troubleshooting guide

Author: vinod0m