Nested completion reproduction — real web app and real server

Both sides: fresh worktree-local data created by T3CODE_DEV_SEED=0 vp run dev.
No copied database, no fixture injection, no unit-test runtime.
Browser viewport 1280x800, light theme, details panel closed.
The parent and descendants run through the same configured provider and runtime selection on each side.
Private provider model identifiers are intentionally omitted from this public package.

Files:
- drive.mjs: same prepare/start/observe driver for both commits.
- rpc.mjs: authenticated MCP transport used by the driver; creates and revokes an isolated client credential without printing it.
- before/after-final-runtime-transcript.json: filtered real t3_thread_read responses, retaining assistant messages, notifications, commands, child task results, and run timestamps/status.
- before/after.mp4: recordings of the app during execution and subsequent inspection of the child and parent.

Run:
1. Install each checkout with vp i and start each with T3CODE_DEV_SEED=0 vp run dev.
2. Set EVIDENCE_PROVIDER and EVIDENCE_MODEL to the same available runtime selection locally.
3. node drive.mjs <worktree> <before|after> prepare
4. Open the returned parent thread in the local web app and start a browser recording.
5. node drive.mjs <worktree> <before|after> start
6. Allow the asynchronous sequence to complete without sending follow-ups or polling task_status.
7. node drive.mjs <worktree> <before|after> observe
8. Inspect child final report, then return to parent and inspect received reports.

Expected sequence:
Parent delegates Child asynchronously and ends its turn.
Child starts `sleep 45; echo BACKGROUND_READY` as a background command, ends with CHILD_INITIAL.
Parent receives CHILD_INITIAL and becomes idle.
Background completion wakes Child. Child delegates Grandchild asynchronously and yields.
Grandchild executes sleep 8 and returns GRANDCHILD_MARKER_28462.
Grandchild completion wakes Child, which returns CHILD_FINAL GRANDCHILD_MARKER_28462.
Observe whether that final result reaches and wakes Parent.

Video processing:
Crop the same 1280x800 recording to x=256,y=0,width=1024,height=650.
This keeps the conversation and breadcrumb while omitting the runtime picker and unrelated sidebar.
Redact the environment label rectangle in the details panel. Add a 44px title bar stating side, commit, viewport, theme, and isolated data.
No transcript content is changed. Videos retain real-time playback.

AI-assisted; verified with the tests and tools listed above.
No tests were used as reproduction evidence.