refactor: consolidate QueryTimer struct to shared header

Move QueryTimer from m2_renderer.cpp and wmo_renderer.cpp to
vk_frame_data.hpp for reuse. Removes 13 lines of duplicate code.

include/rendering/vk_frame_data.hpp

@@ -2,6 +2,7 @@
 
 #include <vulkan/vulkan.h>
 #include <glm/glm.hpp>
+#include <chrono>
 
 namespace wowee {
 namespace rendering {
@@ -41,5 +42,22 @@ struct ShadowParamsUBO {
     float foliageMotionDamp;
 };
 
+// Timer utility for performance profiling queries
+struct QueryTimer {
+    double* totalMs = nullptr;
+    uint32_t* callCount = nullptr;
+    std::chrono::steady_clock::time_point start = std::chrono::steady_clock::now();
+    QueryTimer(double* total, uint32_t* calls) : totalMs(total), callCount(calls) {}
+    ~QueryTimer() {
+        if (callCount) {
+            (*callCount)++;
+        }
+        if (totalMs) {
+            auto end = std::chrono::steady_clock::now();
+            *totalMs += std::chrono::duration<double, std::milli>(end - start).count();
+        }
+    }
+};
+
 } // namespace rendering
 } // namespace wowee

src/rendering/m2_renderer.cpp

@@ -192,22 +192,6 @@ float pointAABBDistanceSq(const glm::vec3& p, const glm::vec3& bmin, const glm::
     return glm::dot(d, d);
 }
 
-struct QueryTimer {
-    double* totalMs = nullptr;
-    uint32_t* callCount = nullptr;
-    std::chrono::steady_clock::time_point start = std::chrono::steady_clock::now();
-    QueryTimer(double* total, uint32_t* calls) : totalMs(total), callCount(calls) {}
-    ~QueryTimer() {
-        if (callCount) {
-            (*callCount)++;
-        }
-        if (totalMs) {
-            auto end = std::chrono::steady_clock::now();
-            *totalMs += std::chrono::duration<double, std::milli>(end - start).count();
-        }
-    }
-};
-
 // Möller–Trumbore ray-triangle intersection.
 // Returns distance along ray if hit, negative if miss.
 float rayTriangleIntersect(const glm::vec3& origin, const glm::vec3& dir,

src/rendering/wmo_renderer.cpp

@@ -2492,22 +2492,6 @@ static float pointAABBDistanceSq(const glm::vec3& p, const glm::vec3& bmin, cons
     return glm::dot(d, d);
 }
 
-struct QueryTimer {
-    double* totalMs = nullptr;
-    uint32_t* callCount = nullptr;
-    std::chrono::steady_clock::time_point start = std::chrono::steady_clock::now();
-    QueryTimer(double* total, uint32_t* calls) : totalMs(total), callCount(calls) {}
-    ~QueryTimer() {
-        if (callCount) {
-            (*callCount)++;
-        }
-        if (totalMs) {
-            auto end = std::chrono::steady_clock::now();
-            *totalMs += std::chrono::duration<double, std::milli>(end - start).count();
-        }
-    }
-};
-
 // Möller–Trumbore ray-triangle intersection
 // Returns distance along ray if hit, or negative if miss
 static float rayTriangleIntersect(const glm::vec3& origin, const glm::vec3& dir,
@@ -3599,12 +3583,13 @@ void WMORenderer::recreatePipelines() {
     }
 
     // --- Vertex input ---
+    // WMO vertex: pos3 + normal3 + texCoord2 + color4 + tangent4 = 64 bytes
     struct WMOVertexData {
         glm::vec3 position;
         glm::vec3 normal;
         glm::vec2 texCoord;
         glm::vec4 color;
-        glm::vec4 tangent;
+        glm::vec4 tangent;  // xyz=tangent dir, w=handedness ±1
     };
 
     VkVertexInputBindingDescription vertexBinding{};