test: tolerant timing assertion in the execution-time measure test

setTimeout can fire a few ms early under load (timer coalescing) — a
10ms sleep measured 9ms and failed the >=10 assertion, tripping a
release gate. Sleep 25ms, assert >=20: the test verifies time is
MEASURED, not the OS timer's precision.

tests/transaction/TransactionManager.unit.test.ts

@@ -105,14 +105,17 @@ describe('TransactionManager', () => {
       const result = await manager.executeTransactionWithResult(async (tx) => {
         tx.addOperation({
           execute: async () => {
-            await new Promise(resolve => setTimeout(resolve, 10))
+            await new Promise(resolve => setTimeout(resolve, 25))
             return async () => {}
           }
         })
         return 'done'
       })
 
-      expect(result.executionTimeMs).toBeGreaterThanOrEqual(10)
+      // Timer coalescing can fire a setTimeout up to a few ms EARLY under
+      // load, so assert well below the sleep — this tests that time is
+      // MEASURED, not the OS timer's precision.
+      expect(result.executionTimeMs).toBeGreaterThanOrEqual(20)
     })
   })