fix(test): stop the eng batching eval once its floor is proven

The case's only verdict is reviewCount >= FLOOR (3). Run 36385945043 had
three distinct acknowledged review decisions at 6m41s but kept answering
until the ceiling (7) at 12m13s. The registration now passes the runner's
existing isCollectionComplete stop once FLOOR non-setup, non-administrative
review decisions are acknowledged; the floor check, ceiling, budget and
counter are unchanged. A child-process registration test proves the stop
predicate and that below-floor and timeout outcomes still fail.

test/skill-e2e-plan-eng-multi-finding-batching.test.ts

@@ -12,7 +12,8 @@
  *     would pass that test trivially.
  *   - This test uses runPlanSkillCounting at periodic tier (~25 min budget,
  *     N-AUQ tracking, ceiling-bounded retries) to actually count distinct
- *     review-phase AUQs and assert the model fires one per finding.
+ *     review-phase AUQs and assert the model fires one per finding. Collection
+ *     stops as soon as the floor is proven (~7 min observed).
  *
  * Why a separate test from skill-e2e-plan-eng-finding-count (the existing
  * 5-finding count test):
@@ -21,7 +22,7 @@
  *     This is the tightest regression test for the original bug class —
  *     not a band-around-N test, but a "did the agent batch?" test.
  *
- * Tier: periodic (~25 min, ~$5/run). Sequential by default.
+ * Tier: periodic (~7 min observed; 25 min budget). Sequential by default.
  */
 
 import { test } from 'bun:test';
@@ -80,12 +81,18 @@ describeE2E('/plan-eng-review multi-finding batching regression (periodic)', ()
           isSetupAUQ: engSetupAUQ,
           isFirstReviewAUQ: engFirstReviewAUQ,
           isReviewAUQ: findings.isReviewAUQ,
+          // The only verdict is the floor. Once FLOOR distinct acknowledged
+          // review decisions exist, a batching regression can no longer occur
+          // in this attempt; stop instead of letting the review run to the
+          // ceiling (run 36385945043: floor at 6m41s, ceiling at 12m13s).
+          isCollectionComplete: (_transcript, fingerprints) =>
+            fingerprints.filter(fp => !fp.preReview && !fp.administrative).length >= FLOOR,
           reviewCountCeiling: N + 3, // hard cap above floor + tolerance
           timeoutMs: 1_500_000, // 25 min
           env: { QUESTION_TUNING: 'false', EXPLAIN_LEVEL: 'default' },
         });
 
-        if (!['plan_ready', 'completion_summary', 'ceiling_reached'].includes(obs.outcome)) {
+        if (!['plan_ready', 'completion_summary', 'collection_complete', 'ceiling_reached'].includes(obs.outcome)) {
           throw new Error(
             `multi-finding batching test FAILED: outcome=${obs.outcome}\n` +
               `step0=${obs.step0Count} review=${obs.reviewCount} elapsed=${obs.elapsedMs}ms\n` +