Adds an opt-in per-sha commit granularity mode to the task-revert git path, alongside its default squash behavior, and merges it cleanly with the existing FN-7524 AI-undo mode support.
- Add `TaskRevertGranularity` ("squash" | "per-sha") and thread an optional `granularity` option through `performTaskRevert`/`PerformTaskRevertOptions`.
- Factor a shared `applyRevertNoCommit` primitive (stage + no-op/conflict detection) used by both the squash and new per-sha apply paths.
- `"per-sha"` creates one attributed `revert(FN-xxxx): ...` commit per original sha (each with its own `Fusion-Task-Id` trailer and audit line), skipping no-op shas without empty commits; a mid-batch conflict rolls the whole batch back to the pre-call HEAD.
- Extend `TaskRevertResult`'s clean shape with `revertCommitShas: string[]` (all created commits) alongside the existing `revertCommitSha`.
- `POST /api/tasks/:id/revert` accepts an optional `granularity` request-body field (default `"squash"`, validated, 400 on unknown values) and forwards it to the engine service; documented alongside the existing `mode` (git/ai/auto) contract.
- Add real-git and route-level test coverage for per-sha creation, no-op skipping, default-squash behavior, and mid-batch conflict rollback.
- Update docs/task-management.md's revert section and add a changeset.
Files changed:
.changeset/fn-7548-per-sha-revert-granularity.md | 7 +
docs/task-management.md | 3 +-
packages/dashboard/src/__tests__/task-revert-route.test.ts | 46 +++++-
packages/dashboard/src/routes/register-task-workflow-routes.ts | 51 ++++--
packages/engine/src/__tests__/task-revert.real-git.test.ts | 124 +++++++++++++++
packages/engine/src/index.ts | 2 +
packages/engine/src/task-revert.ts | 176 +++++++++++++++++----
7 files changed, 359 insertions(+), 50 deletions(-)
Fusion-Task-Id: FN-7548
Fusion-Task-Lineage: b9548f5e-fcc2-45d4-98e0-dd7340928208
Co-authored-by: Fusion (runfusion.ai) <noreply@runfusion.ai>