Mollified runs were materialising with `TaskRun.traceContext = {}`, so every
downstream `recordRunDebugLog` (engine QUEUED/EXECUTING/FINISHED, run:notify,
attempt events) drew a fresh traceId with null parentId. The run-detail
trace view rendered only the root span; the rest of the tree was orphaned.
The pass-through path gets traceContext for free via `traceEventConcern.traceRun`
populating the W3C traceparent. The mollifier path skips that wrapper, so seed
`traceContext.traceparent` from the queued span at the call site before
handing the snapshot to engine.trigger.
Also fixes the drainer side: wrap the `mollifier.drained` span + `engine.trigger`
call in a `context.with(parentContext, ...)` built from the snapshot's
traceId/spanId. Without this `mollifier.drained` lived in a fresh trace and
the engine instrumentation inside it inherited an empty active context.
Regression tests:
- `triggerTask.test.ts` — asserts the buffered snapshot carries a valid W3C
traceparent that references the snapshot's traceId/spanId.
- `mollifierDrainerHandler.test.ts` — captures the active traceId at the
moment engine.trigger is invoked and asserts it matches the snapshot's
traceId.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Dan Sutton
854bf38e8a