Document installer release architecture

autoinstall/offline/README.md

@@ -4,6 +4,17 @@ This directory defines the payload embedded by `build-iso-offline.sh`. The
 offline installer is deliberately separate from the existing online bootstrap
 ISO until disconnected clean-install validation is complete.
 
+The agreed bootable release matrix is:
+
+1. Online Universal Server ISO with Server S/M/L/Max selection.
+2. Offline Workstation ISO.
+3. Offline Server S/M ISO.
+4. Offline Server L/Max ISO.
+
+Large models remain separate signed model packs. Signed update bundles patch
+installed appliances without an operating-system reinstall, and validated
+updates are periodically rolled into refreshed ISO builds.
+
 ## Offline Workstation contents
 
 - the exact `aipackage` source revision used for the build