The end-user shell — knowledge queries and agent chat in the browser. A thin client: the conversation and the answer are run by Query Engine through the shared API, sign-in and identity by Auth / Security. Web App's own job is to assemble the surface: the shell, an off-the-shelf chat shell, and our domain layer inside it.
The screen is assembled from three ownership layers — outside in:
Screens — a description and wireframe of each.