- Added details for Issue #53 regarding the audit of activity placeholders between Layer 1 and Layer 2a in `CLAUDE.md` and `README.md`.
- Updated the `ACTIVITY_SESSION_METRICS_EAV_AGENT_GUIDE.md` to reflect the new registry checks and dynamic session metrics handling.
- Revised the `placeholder_resolver.py` and `activity_metrics.py` to clarify the registration of activity metrics and session insights, ensuring consistency in the handling of dynamic keys and metrics.
- Improved descriptions and semantic contracts in `activity_session_insights.py` to better outline the structure and limitations of session data.
