fix(e2e,store,delivery): fix E2E stability - lifecycle ordering, event ordering, callback_target NOT NULL, worker ticker loop

test/e2e/sub2api_callback_flow_test.go

@@ -132,7 +132,7 @@ func waitForSessionEvents(t *testing.T, timeout time.Duration, eventsCh <-chan p
 			if len(filtered) == want {
 				return filtered
 			}
-		case <-time.After(200 * time.Millisecond):
+		case <-time.After(50 * time.Millisecond):
 		}
 	}
 
@@ -159,7 +159,11 @@ func TestSub2APICallbackFlow_ShouldDeliverOrderedEventsWithStableEventIDs(t *tes
 		if err := json.NewDecoder(r.Body).Decode(&event); err != nil {
 			t.Fatalf("decode callback body failed: %v", err)
 		}
-		eventsCh <- event
+		select {
+		case eventsCh <- event:
+		case <-time.After(5 * time.Second):
+			t.Fatalf("eventsCh send timeout")
+		}
 		w.WriteHeader(http.StatusOK)
 	}))
 	defer callbackServer.Close()
@@ -205,6 +209,7 @@ func TestSub2APICallbackFlow_ShouldDeliverOrderedEventsWithStableEventIDs(t *tes
 	}
 
 	filtered := waitForSessionEvents(t, 8*time.Second, eventsCh, sessionID, 6)
+
 	wantTypes := []string{
 		platformevent.TypeMessageReceived,
 		platformevent.TypeMessageProcessing,