test(integrationtests): increase SDK key expiry margin and big-segment sync timeout (#711)

Reduces flaky Integration Tests - staging failures by relaxing two timing constants only in tests—no production Relay behavior changes.

In testSDKKeyExpires, the deprecated-key grace period is increased from 5s to 30s so sequential rotateSDKKeys calls (one per environment) still send a future expiry to staging after CI latency and clock skew; the test still sleeps only until keys expire before asserting cleanup.

In verifyEvaluationWithBigSegment, the assert.Eventually poll window is increased from 20s to 60s so a second big-segment update can propagate via streaming in slow environments; passing runs still exit as soon as evaluations match.

Author: aaron-zeisler

integrationtests/big_segments_test.go

@@ -110,7 +110,8 @@ func verifyEvaluationWithBigSegment(
 	// Poll the evaluation endpoint until we see the expected flag values. We're using a
 	// longer timeout here than we use in tests that don't involve big segments, because
 	// the user segment state caching inside the SDK makes it hard to say how soon we'll
-	// see the effect of an update.
+	// see the effect of an update. 60s gives enough headroom for streaming propagation
+	// of a second segment update to complete in staging CI environments.
 	success := assert.Eventually(t, func() bool {
 		ok := true
 		for i, env := range environments {
@@ -125,7 +126,7 @@ func verifyEvaluationWithBigSegment(
 			}
 		}
 		return ok
-	}, time.Second*20, time.Millisecond*100, "Did not see expected flag values from Relay")
+	}, time.Second*60, time.Millisecond*100, "Did not see expected flag values from Relay")
 
 	if !success {
 		manager.loggers.Infof("EXPLANATION OF TEST FAILURE FOLLOWS:")

integrationtests/offline_mode_test.go

@@ -168,7 +168,11 @@ func testSDKKeyExpires(t *testing.T, manager *integrationTestManager) {
 			fileName := "archive.tar.gz"
 			filePath := filepath.Join(manager.relaySharedDir, fileName)
 
-			const keyGracePeriod = 5 * time.Second
+			// 30s gives plenty of margin for multiple sequential staging API calls to succeed
+			// even with round-trip latency and clock skew between the CI runner and staging.
+			// Previously 5s was too tight: the second rotateSDKKey call could arrive at staging
+			// with an expiry at-or-before "now", causing a 400 Bad Request.
+			const keyGracePeriod = 30 * time.Second
 			// Relay will check for expired keys at this interval.
 			const cleanupInterval = 100 * time.Millisecond