Fix real bugs found by clang-tidy

- game_handler.cpp: use-after-move on node.id after std::move(node)
  (save nodeId before the move)
- tcp_socket.cpp, world_socket.cpp: virtual call in destructor bypasses
  dispatch; use qualified TCPSocket::disconnect() / WorldSocket::disconnect()
  to make intent explicit
- wmo_renderer.cpp: float loop counters risk precision drift; replace with
  integer step counts and reconstruct float from index
- game_screen.cpp: (float + 0.5) cast to int is incorrect rounding;
  use std::lround instead

src/ui/game_screen.cpp

@@ -5462,7 +5462,7 @@ void GameScreen::renderSettingsWindow() {
                 break;
             }
         }
-        pendingUiOpacity = static_cast<int>(uiOpacity_ * 100.0f + 0.5f);
+        pendingUiOpacity = static_cast<int>(std::lround(uiOpacity_ * 100.0f));
         pendingMinimapRotate = minimapRotate_;
         pendingMinimapSquare = minimapSquare_;
         if (renderer) {