docs: add session continuation summary

Add comprehensive summary of documentation work completed in this
autonomous continuation session:

- Overview of three major documentation files added
  * ADVANCED_FEATURES.md (400+ lines)
  * DEPLOYMENT.md (500+ lines)
  * PERFORMANCE.md (600+ lines)

- Detailed breakdown of contents and value for each guide
- Statistics: 1,500+ lines of documentation added
- Complete project stats: 15,000+ words total documentation
- Git activity summary and commit details
- Impact assessment and recommendations
- Suggested next steps for user

This summary provides a clear record of the continuation session's
deliverables and helps the user understand what was accomplished
beyond the original autonomous development work.

Total autonomous work across both sessions:
- Code: 7,500+ lines, 10 modules, 69+ tests
- Docs: 15,000+ words, 8 major documents
- Examples: 3 runnable demonstrations
- Benchmarks: 3 performance suites

Author: claude