- Replace all STEAM branding with AEGIS (Advanced Engineering Group
Intelligence System) across login, header, nav drawer, manifest, and
browser title
- Add shield logo to login page, main header, and nav drawer
- Fix BU drift checker recording incorrect previous_bu values by
building a previousBuMap snapshot BEFORE the upsert/delete cycle
instead of querying the DB after rows are already gone
- Clean 526 bogus BU history entries generated by the broken logic
- Add docs and scripts from prior session
