docs: publish 5.5 release status and Engine 6 Preview access
docs: record public Preview access and verified restoration
docs: verify CodeQL alert 91 fixed after merge
docs: publish merged CodeQL correction and new cohort boundary
docs: record full regression and offline replay for table fix
docs: distinguish table-encoding candidate from hosted preview
Record hosted report rendering and pending browser export
Document verified private Engine 6 Preview deployment
Refresh documentation for stable 5.2 and Engine 6 Preview qualification