fix: critical Keep-Alive correlation bug - network events evicted prematurely

- Fix cleanExpired() to use TTL map instead of event timestamp for B events
- Increase default correlation time window from 1s to 10s
- Increase default network TTL from 30s to 120s for long sessions
- Use payload timestamp for network events when available (fallback to now)
- Add comprehensive Keep-Alive tests (TTL reset, long session scenarios)
- Bump version to 1.1.7

Co-authored-by: Qwen-Coder <qwen-coder@alibabacloud.com>

internal/config/config_test.go

@@ -719,8 +719,8 @@ func TestCorrelationConfig_GetNetworkTTLS_Default(t *testing.T) {
 	}
 
 	result := cfg.GetNetworkTTLS()
-	if result != 30 {
-		t.Errorf("expected default 30, got %d", result)
+	if result != 120 {
+		t.Errorf("expected default 120, got %d", result)
 	}
 }