ChatGPT can omit nullable nested fields from structured tool results and does not reliably expose result metadata to MCP Apps. Keep graph data in `structuredContent`, tolerate missing document titles, and bundle React inside the widget so the graph renders consistently across hosts.
- use the deployable `app-v4` resource URI
- keep the graph response and widget schema aligned
- remove the `esm.sh` runtime dependency
Tested with typecheck, 42 unit tests, production widget build, 36 branch-local authenticated E2E tests, and a live ChatGPT graph render.