Fixes cross-host graph rendering and moves widget uploads off the JSON/base64 tool transport.
- render graph data from the launcher result without a second tool call
- stream multipart uploads through one-time, short-lived upload sessions
- remove temporary widget diagnostics and redundant unit tests
Tested with Biome, TypeScript, 17 unit tests, a Wrangler deployment dry-run, and live graph rendering in ChatGPT and Claude. Authenticated E2E setup is currently blocked by the saved OAuth refresh session returning `invalid_grant: session not found`.