feat: add WotLK vehicle exit UI with Leave Vehicle button

Parse SMSG_PLAYER_VEHICLE_DATA (PackedGuid + uint32 vehicleId) and
track in-vehicle state. Add sendRequestVehicleExit() which sends
CMSG_REQUEST_VEHICLE_EXIT. Render a floating red "Leave Vehicle"
button above the action bar whenever vehicleId_ is non-zero.
State cleared on world leave and zone transfer.

include/game/game_handler.hpp

@@ -1594,6 +1594,11 @@ public:
         return it != taxiNpcHasRoutes_.end() && it->second;
     }
 
+    // Vehicle (WotLK)
+    bool isInVehicle() const { return vehicleId_ != 0; }
+    uint32_t getVehicleId() const { return vehicleId_; }
+    void sendRequestVehicleExit();
+
     // Vendor
     void openVendor(uint64_t npcGuid);
     void closeVendor();
@@ -2536,6 +2541,9 @@ private:
         return it != factionHostileMap_.end() ? it->second : true; // default hostile if unknown
     }
 
+    // Vehicle (WotLK): non-zero when player is seated in a vehicle
+    uint32_t vehicleId_ = 0;
+
     // Taxi / Flight Paths
     std::unordered_map<uint64_t, bool> taxiNpcHasRoutes_;  // guid -> has new/available routes
     std::unordered_map<uint32_t, TaxiNode> taxiNodes_;

src/game/game_handler.cpp

@@ -5211,10 +5211,19 @@ void GameHandler::handlePacket(network::Packet& packet) {
             // GM ticket status (new/updated); no ticket UI yet
             packet.setReadPos(packet.getSize());
             break;
-        case Opcode::SMSG_PLAYER_VEHICLE_DATA:
-            // Vehicle data update for player in vehicle; no vehicle UI yet
-            packet.setReadPos(packet.getSize());
+        case Opcode::SMSG_PLAYER_VEHICLE_DATA: {
+            // PackedGuid (player guid) + uint32 vehicleId
+            // vehicleId == 0 means the player left the vehicle
+            if (packet.getSize() - packet.getReadPos() >= 1) {
+                (void)UpdateObjectParser::readPackedGuid(packet); // player guid (unused)
+            }
+            if (packet.getSize() - packet.getReadPos() >= 4) {
+                vehicleId_ = packet.readUInt32();
+            } else {
+                vehicleId_ = 0;
+            }
             break;
+        }
         case Opcode::SMSG_SET_EXTRA_AURA_INFO_NEED_UPDATE:
             packet.setReadPos(packet.getSize());
             break;
@@ -6868,6 +6877,7 @@ void GameHandler::handleLoginVerifyWorld(network::Packet& packet) {
     taxiStartGrace_ = 0.0f;
     currentMountDisplayId_ = 0;
     taxiMountDisplayId_ = 0;
+    vehicleId_ = 0;
     if (mountCallback_) {
         mountCallback_(0);
     }
@@ -7891,6 +7901,14 @@ void GameHandler::sendPing() {
     socket->send(packet);
 }
 
+void GameHandler::sendRequestVehicleExit() {
+    if (state != WorldState::IN_WORLD || vehicleId_ == 0) return;
+    // CMSG_REQUEST_VEHICLE_EXIT has no payload — opcode only
+    network::Packet pkt(wireOpcode(Opcode::CMSG_REQUEST_VEHICLE_EXIT));
+    socket->send(pkt);
+    vehicleId_ = 0;  // Optimistically clear; server will confirm via SMSG_PLAYER_VEHICLE_DATA(0)
+}
+
 void GameHandler::sendMinimapPing(float wowX, float wowY) {
     if (state != WorldState::IN_WORLD) return;
 
@@ -8202,6 +8220,7 @@ void GameHandler::forceClearTaxiAndMovementState() {
     taxiMountActive_ = false;
     taxiMountDisplayId_ = 0;
     currentMountDisplayId_ = 0;
+    vehicleId_ = 0;
     resurrectPending_ = false;
     resurrectRequestPending_ = false;
     playerDead_ = false;

src/ui/game_screen.cpp

@@ -6968,6 +6968,38 @@ void GameScreen::renderActionBar(game::GameHandler& gameHandler) {
         ImGui::PopStyleVar(4);
     }
 
+    // Vehicle exit button (WotLK): floating button above action bar when player is in a vehicle
+    if (gameHandler.isInVehicle()) {
+        const float btnW = 120.0f;
+        const float btnH = 32.0f;
+        const float btnX = (screenW - btnW) / 2.0f;
+        const float btnY = barY - btnH - 6.0f;
+
+        ImGui::SetNextWindowPos(ImVec2(btnX, btnY), ImGuiCond_Always);
+        ImGui::SetNextWindowSize(ImVec2(btnW, btnH), ImGuiCond_Always);
+        ImGui::PushStyleVar(ImGuiStyleVar_WindowRounding, 4.0f);
+        ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding, ImVec2(4.0f, 4.0f));
+        ImGui::PushStyleVar(ImGuiStyleVar_WindowBorderSize, 0.0f);
+        ImGui::PushStyleColor(ImGuiCol_WindowBg, ImVec4(0.0f, 0.0f, 0.0f, 0.0f));
+        ImGuiWindowFlags vFlags = ImGuiWindowFlags_NoResize | ImGuiWindowFlags_NoMove |
+                                  ImGuiWindowFlags_NoCollapse | ImGuiWindowFlags_NoTitleBar |
+                                  ImGuiWindowFlags_NoScrollbar | ImGuiWindowFlags_NoBackground;
+        if (ImGui::Begin("##VehicleExit", nullptr, vFlags)) {
+            ImGui::PushStyleColor(ImGuiCol_Button,        ImVec4(0.6f, 0.1f, 0.1f, 0.9f));
+            ImGui::PushStyleColor(ImGuiCol_ButtonHovered, ImVec4(0.8f, 0.2f, 0.2f, 1.0f));
+            ImGui::PushStyleColor(ImGuiCol_ButtonActive,  ImVec4(0.4f, 0.0f, 0.0f, 1.0f));
+            ImGui::PushStyleVar(ImGuiStyleVar_FrameRounding, 4.0f);
+            if (ImGui::Button("Leave Vehicle", ImVec2(btnW - 8.0f, btnH - 8.0f))) {
+                gameHandler.sendRequestVehicleExit();
+            }
+            ImGui::PopStyleVar();
+            ImGui::PopStyleColor(3);
+        }
+        ImGui::End();
+        ImGui::PopStyleColor();
+        ImGui::PopStyleVar(3);
+    }
+
     // Handle action bar drag: render icon at cursor and detect drop outside
     if (actionBarDragSlot_ >= 0) {
         ImVec2 mousePos = ImGui::GetMousePos();