Fix Deeprun Tram: visual movement, direction, and player riding

- Fix NULL renderer pointers by moving TransportManager connection after
  initializeRenderers for WMO-only maps
- Fix tram direction by negating DBC TransportAnimation X/Y local offsets
  before serverToCanonical conversion
- Implement client-side M2 transport boarding via proximity detection
  (server doesn't send transport attachment for trams)
- Use position-delta approach: player keeps normal movement while
  transport's frame-to-frame motion is applied on top
- Prevent server movement packets from clearing client-side M2 transport
  state (isClientM2Transport guard)
- Fix getPlayerWorldPosition for M2 transports: simple canonical addition
  instead of render-space matrix multiplication

include/game/game_handler.hpp

@@ -658,6 +658,9 @@ public:
         playerTransportStickyTimer_ = 8.0f;
         movementInfo.transportGuid = transportGuid;
     }
+    void setPlayerTransportOffset(const glm::vec3& offset) {
+        playerTransportOffset_ = offset;
+    }
     void clearPlayerTransport() {
         if (playerTransportGuid_ != 0) {
             playerTransportStickyGuid_ = playerTransportGuid_;