Per user feedback: admin/review/ai-image-gen/ai-chat are completely new independent systems with their own codebases and DBs, not reusing existing services. They only have API-level calls between each other and to existing services. Section 1.3 table and 'key clarification' paragraph updated. Other 'shared' references in the document refer to the platform-architecture sense (shared services for all groups), not code reuse, so no other changes needed.
Three approaches analyzed (single-tenant, hybrid, full-isolation), with detailed pros/cons comparison. Recommended: shared platform services + per-group data services isolation via namespaces and Helm chart.
