Follows **#2519** (U8 PR4). Both halves are inert — **no behavior
change** — and this removes the blocker PR4 documented.
## What was blocking
PR4 could only land its IR half because the pending-review ending could
not reach a graph edge on the **default** workflow. Three links in the
chain:
| Link | Problem |
|---|---|
| `runGraphTaskStep` | awaited the memoized implementation pass and
**discarded** its result |
| `RunTaskStepResult` / `RunSingleStep` | had nowhere to carry an exit |
| `stepExecute` seam | flattened every ending to `step-done` /
`step-failed` |
All three are fixed. The outcome stays `failure` (the step genuinely did
not complete) while the **value** now names the ending — which is what
`runForeach` propagates upward, since it returns a failing instance's
value as the foreach node's own. Every other ending keeps `step-failed`
byte-identically.
One design note: the exit is a property of the **pass**, not of a step.
A single memoized pass serves every foreach instance, so all instances
report the same ending — correct, because the ending is what stopped the
whole session.
With the value surviving, the stepwise IR declares the same
`review-handoff` park node and `steps --outcome:review-pending-->
review-pending-handoff --success--> end` edge the plain-`execute` shape
got in PR4, inherited by the final-review and Ideas variants that clone
it.
## A bug my own threading introduced, and what caught it
The first threading commit covered **one of the two** paths out of
`runProjectedGraphTaskStep`. The early-return branch carried the exit;
the main path goes through `runTaskStep` in `step-runner.ts`, which
builds its own result and dropped it — i.e. it worked on the path I
happened to read, and not on the path the default workflow actually
takes.
**FN-5436's regression test caught it, not code review.** That is the
second time this test has stood between this unit and a silent
regression, which is worth recording somewhere durable:
`executor-step-session.test.ts > FN-5436: pending-review skip on
no-fn_task_done exit` is the load-bearing test for this area.
## Why the seam flip is still not here
With the threading complete I applied the behavior half again — flip the
execute seam to return `review-pending`, delete the inline
`handoffTaskToReview`, add a named compat classifier for user-authored
graphs. **FN-5436 still failed**: the card did not reach `in-review`, so
something between the seam value and the park node is not routing under
that harness. I have not isolated whether that is the mock store's IR
resolution (it exposes no `getWorkflowDefinition`, so the run resolves
the built-in through a different path), a foreach aggregation detail, or
the park node's own seam.
I stopped rather than keep guessing, and reverted the behavior edits so
this lands green and inert. Shipping a half-routed move is exactly the
failure this unit exists to remove — a lifecycle transition that
silently does not happen. The alternative on offer was to relax
FN-5436's assertion, which would have been appeasing a test that is
telling the truth.
### What the instrumentation showed (done after opening this PR)
I ran the bounded next step rather than leaving it as a note. Two facts,
both measured:
1. **The IR is correct.** Resolving
`BUILTIN_STEPWISE_FINAL_REVIEW_CODING_WORKFLOW_IR` at runtime shows the
node and the edge survive the final-review variant's edge rewiring:
```
EDGES [{"from":"steps","to":"browser-verification","condition":"success"},
{"from":"steps","to":"review-pending-handoff","condition":"outcome:review-pending"},
{"from":"steps","to":"end","condition":"failure"}]
HAS NODE true
```
That matters because the variant does `template.edges = [ ... ]` (a
wholesale replacement) and filters outer edges touching `review` —
`review-pending-handoff` is not `review`, so it survives. Worth knowing
before anyone adds another node near it.
2. **The `stepExecute` seam is never invoked in that harness**, even
though the run terminates at `steps#0:step-execute` and the
implementation session demonstrably runs (`"Agent finished without
calling fn_task_done but Step 0 is blocked on pending review"` is in the
task log). A `console.log` at the seam's value computation produced no
output. So the exit is threaded correctly and the IR can route it, but
under this harness the value never originates.
3. **Nor is `createPromptLikeHandler`'s returned handler.**
Instrumenting its dispatch (`node.id` + resolved seam) produced nothing
either — so the node is not reaching the prompt-like path at all.
**Control experiment, because a negative result from instrumentation is
worthless until you prove the instrumentation is observable.** A
`process.stderr.write` at module load of the same file appears exactly
once in the same run, so writes from that module *are* captured under
this harness and the two negatives above are real, not artifacts of
swallowed output.
That narrows the remaining work to one question — what actually drives
`steps#0:step-execute` in this run, if neither the prompt-like handler
nor the `stepExecute` seam does — and rules out the IR, the foreach
propagation, the threading, and the instrumentation as suspects.
**Next step, now much narrower:** find the handler registration this run
resolves for a foreach instance node (the graph executor's handler map,
not the seam table), then flip the seam, delete the inline handoff, and
update the three ratchets that will correctly fire — PR3's routing pin,
the out-of-band adjacency check, and PR1's ownership ledger
(`runImplementation` 3 → 2; `handleGraphFailure` 0 → 1 for custom graphs
only).
## Verification
- `executor-step-session` + exit-events + ownership ledger +
graph-boundary — **56 tests green**
- `builtin-workflows` + `builtin-coding-workflow-ir` — green. The
layout-completeness contract required a layout entry for the new node in
all four stepwise-derived workflows; placed off the main line, because a
park is an exit and not a stage.
- `pnpm test:gate` green (10 / 309 / 71); `pnpm lint` clean; `tsc
--noEmit` clean
- Changeset included (`patch`, `internal`)
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
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