Add new sections to xattn_bsa_policy_design.md:
- Performance benchmarks: 128K context comparison (Full vs XAttn BSA)
- Density trend analysis across chunks
- Memory leak issue and fix (64GB -> 4GB reduction)
- Memory monitoring guide with gpu-monitor agent
- Density statistics API documentation
- Known issues and optimization directions
Update CLAUDE.md description to reflect new content.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>