Update README feature list with GDPR compliance system details. Update Overview.md Data & Compliance section with full Article 15 SAR details. Update Technical Manual: add /gdpr route, gdpr_export.go handler, GET /api/user/gdpr-export endpoint, update Key Functions table, update Guest User System section. Update Future Work backlog: mark #7 GDPR export as complete, update dependency map and Phase 3 execution order. Update test count: 446/449 -> 576/579.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
popertotsandSisyphus
6cc65341a0