fusion

Files

gsxdsm a013bc0309 FN-6607: align step tools with zero-based prompt steps

Align executor step tools and review bookkeeping with the 0-based Step N labels agents see in PROMPT.md.

- Treat fn_task_update and fn_review_step step parameters as 0-indexed values, including validation, logs, checkpoints, and review verdict maps.
- Update executor/reviewer/step-runner guidance and generated tool docs to describe Step 0 semantics consistently.
- Adjust affected executor and reliability tests and add coverage proving Step 0 progress, review, and revise handling work without off-by-one shifts.
- Add a patch changeset for the published Fusion CLI package.

Files changed:
 .changeset/fn-6607-step-numbering.md               |   5 +
 .../cli/skill/fusion/references/engine-tools.md    |   4 +-
 .../engine/src/__tests__/executor-pause.test.ts    |   2 +-
 .../executor-review-step-indexing.test.ts          |  18 +-
 .../src/__tests__/executor-review-verdicts.test.ts |  18 +-
 .../executor-step-numbering-zero-based.test.ts     | 196 +++++++++++++++++++++
 .../src/__tests__/executor-step-session.test.ts    |  24 ++-
 ...executor-task-done-revise-verdict-guard.test.ts |   4 +-
 .../executor-pending-review-skip-retry.test.ts     |   8 +-
 .../task-done-refusal-x-invariant.test.ts          |   2 +-
 packages/engine/src/__tests__/step-runner.test.ts  |   4 +-
 packages/engine/src/executor.ts                    |  57 +++---
 packages/engine/src/reviewer.ts                    |   3 +
 packages/engine/src/step-runner.ts                 |   6 +-
 14 files changed, 284 insertions(+), 67 deletions(-)

Fusion-Task-Id: FN-6607

Fusion-Task-Lineage: 1b1fb1d8-07ca-4a33-84f5-1dab83388c01

2026-06-17 19:52:20 -07:00