diff --git a/packages/engine/src/__tests__/self-healing-db-corruption.test.ts b/packages/engine/src/__tests__/self-healing-db-corruption.test.ts
index 8d42d6d549..439f79b9ac 100644
--- a/packages/engine/src/__tests__/self-healing-db-corruption.test.ts
+++ b/packages/engine/src/__tests__/self-healing-db-corruption.test.ts
@@ -123,6 +123,31 @@ function stubMaintenance(manager: SelfHealingManager) {
   for (const method of BATCH2_METHODS) {
     vi.spyOn(manager as never, method).mockResolvedValue(0 as never);
   }
+  /*
+  FNXC:TestInfrastructure 2026-08-01-23:05 (the suite exited 1 with ZERO failing tests):
+  STUBBING THE SWEEPS IS NOT ENOUGH — the shared surfacing cycle is built in the ARGUMENT.
+  `runMaintenance` invokes the surfacing family as `() => this.surfaceInReviewStalled(maintenanceSurfacing())`,
+  and `maintenanceSurfacing()` lazily calls `openSurfacingCycle()`, which does
+  `await this.store.listTasks({ slim: false })`. Spying on `surfaceInReviewStalled` replaces the
+  METHOD but the call site still evaluates its argument, so the cycle opened anyway against a mock
+  store that deliberately implements only what corruption surfacing needs.
+
+  The result was nine `TypeError: this.store.listTasks is not a function` UNHANDLED REJECTIONS raised
+  after the tests had already passed: `engine-default` exited 1 while reporting 736 files passed and
+  0 failed. Worse than a plain failure — the lane is red, nothing names a test, and a real regression
+  arriving later reads as more of the same noise.
+
+  Two fixes that look right and are not, both tried and reverted:
+    adding `listTasks` to the mock   -> 3 tests fail; the sweeps then run far enough to record audit
+                                        events the assertions do not expect.
+    stubbing the 27 maintenance      -> 5 tests fail AND all nine errors remain, because
+    methods missing from the lists      `openSurfacingCycle` is not among `runMaintenance`'s own calls.
+
+  Stubbing the cycle is the honest seam: `null` is exactly what it returns when the engine is paused,
+  so every consumer already handles it, and the corruption path this suite exists to test is
+  untouched.
+  */
+  vi.spyOn(manager as never, "openSurfacingCycle").mockResolvedValue(null as never);
   vi.spyOn(manager, "archiveStaleDoneTasks").mockResolvedValue(0);
 }