**U9, PR10.** Two `package.json` lines. No test or production changes —
this only decides *when* existing tests run.
## The gap
Two U9 safeguards are well covered but sat in **no blocking gate**.
Their proof lives in `packages/core/src/__tests__/task-merge.test.ts`,
and core's only gate job is `test:pg-gate` (two PG tests). A regression
in either surfaced in non-blocking full-suite — after the merge.
## What's now gated, each verified by mutation delta
**`task-merge.test.ts`**
| Invariant | Mutation | NEW failures |
|---|---|---|
| Safeguard 3 — dependency gating | `getTaskCompletionBlocker` drops the
unresolved-dependency reason | **5** |
| FN-5819 — exception bounded to a live group | drop `group.status ===
"open"` | **1** |
| FN-5819 — exception bounded to shared members | widen
`isSharedBranchGroupMemberIntegration` to every task | **4** |
Both FN-5819 directions matter. This is the **only** scoped exception to
`autoMerge:false`, so its *narrowness* is the invariant — not merely its
existence. A test that only proves the exception works would pass while
the exception swallowed every task.
**`legacy-adoption.test.ts`**
| Invariant | Mutation | NEW failures |
|---|---|---|
| FN-8492 — orphaned pending results REWRITTEN to failed, never DELETED
| delete instead of rewrite | **2** |
That one matters because deletion *silently satisfies* the merge gate:
the gate blocks on pending/failed results, not on an enabled step with
no result, so deleting lets a task merge with its review skipped.
## Implementation
Adds `packages/core` → `test:unit-gate`, a curated **non-PG allow-list**
mirroring `engine-core`'s discipline (explicit membership, not a glob),
run as a third parallel job in the root `test:gate` block alongside the
engine and PG jobs.
**Gate fires — verified, not assumed:**
- drop the dependency reason → `pnpm test:gate` **exits 1**
- drop the FN-5819 open-group bound → **exits 1**
- restored → **exits 0**
## Cost: no measurable increase
| | Runs |
|---|---|
| baseline | 13.07s, 14.95s |
| with the job | 12.20s, 12.58s |
It runs in parallel with the existing jobs and finishes well inside
them, so the delta sits inside run-to-run variance. **I am not claiming
a speedup** — the honest reading is "no measurable cost", and the
variance band here is wider than the change.
## Reversible call made rather than asked
A new `test:unit-gate` script rather than widening `test:pg-gate` or
adding a glob. `test:pg-gate` carries PG setup these pure unit tests do
not need, and a glob would admit all of core by default — which
AGENTS.md explicitly forbids ("tests never graduate into the gate by
default"). Membership stays explicit so the next addition has to state
its evidence.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
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