chore: bump version to v2026.4.319 and update changelog}
- Bump version from v2026.4.318 to v2026.4.319 in package.json
- Make all features free by removing license requirements (ReJSON, SSH tunneling, Cluster/Sentinel, etc.)
- Add "All Features Are Free" section to README
- Move ReJSON support documentation out of license-gated section
- Comment out license integration and enforcement sections in README
- Add changelog entry for v2026.4.319
- Update build version footer across all documentation files