[Fix] (MG_Backend/DirectVulkan): support Voxy rendering

Implemented:

- Advertise Voxy-required DirectVulkan extensions without raising the reported OpenGL version.

- Add DirectVulkan compute, indirect draw count, DSA, readback, and buffer state paths needed by Voxy.

Fixed:

- Enable Vulkan shaderInt64 and drawIndirectFirstInstance so Voxy baseInstance-driven LOD draws address the correct section data.

- Fix DirectVulkan synchronization, framebuffer, texture readback, and shader interface handling used by Voxy and Minecraft screenshots.

Tests:

- Add MG_Test coverage for DirectVulkan extension advertising, DSA buffer/texture/framebuffer/vertex-array behavior, persistent mapped readback, and shader/program paths.

MobileGL/MG_Util/BackendLoaders/Vulkan/Loader.cpp

@@ -83,6 +83,7 @@ namespace MobileGL::MG_Util::BackendLoader {
         caps.DeviceName = p.deviceName;
         caps.DriverVersionString = DecodeDriverVersion(p.driverVersion);
         caps.UniformBufferOffsetAlignment = static_cast<int>(p.limits.minUniformBufferOffsetAlignment);
+        caps.MaxShaderStorageBlockSize = static_cast<SizeT>(p.limits.maxStorageBufferRange);
 
         return true;
     }
@@ -93,5 +94,6 @@ namespace MobileGL::MG_Util::BackendLoader {
         caps.DeviceName = properties.deviceName;
         caps.DriverVersionString = DecodeDriverVersion(properties.driverVersion);
         caps.UniformBufferOffsetAlignment = static_cast<int>(properties.limits.minUniformBufferOffsetAlignment);
+        caps.MaxShaderStorageBlockSize = static_cast<SizeT>(properties.limits.maxStorageBufferRange);
     }
 } // namespace MobileGL::MG_Util::BackendLoader