fix: VK_INDEX_TYPE_UINT32 (was UINT16) + remove unused depth from pipeline

- vkCmdBindIndexBuffer indexType changed from 0 (UINT16) to 1 (UINT32)
  to match uint[] index data — this was causing black screen
- Removed depth stencil state, depth attachment format, and depth
  rendering attachment from pipeline/renderer (depth buffer still
  created in swapchain but unused)

src/Engine.Graphics.Vulkan/VulkanPipeline.cs

@@ -14,7 +14,7 @@ internal sealed unsafe class VulkanPipeline : IDisposable
     private readonly VkDevice _device;
     private bool _disposed;
 
-    public VulkanPipeline(VkDevice device, VkFormat colorFormat, VkFormat depthFormat, byte[] vertSpv, byte[] fragSpv)
+    public VulkanPipeline(VkDevice device, VkFormat colorFormat, byte[] vertSpv, byte[] fragSpv)
     {
         _device = device;
         VertModule = CreateShaderModule(vertSpv);
@@ -115,16 +115,6 @@ internal sealed unsafe class VulkanPipeline : IDisposable
                 sampleShadingEnable = VkBool32.False,
             };
 
-            var depthStencilState = new VkPipelineDepthStencilStateCreateInfo
-            {
-                sType = VkStructureType.PipelineDepthStencilStateCreateInfo,
-                depthTestEnable = VkBool32.False,
-                depthWriteEnable = VkBool32.False,
-                depthCompareOp = VkCompareOp.Less,
-                depthBoundsTestEnable = VkBool32.False,
-                stencilTestEnable = VkBool32.False,
-            };
-
             var blendAttachment = new VkPipelineColorBlendAttachmentState
             {
                 blendEnable = VkBool32.False,
@@ -154,7 +144,7 @@ internal sealed unsafe class VulkanPipeline : IDisposable
             {
                 stageFlags = VkShaderStageFlags.Vertex,
                 offset = 0,
-                size = 64,
+                size = 4,
             };
 
             var descLayout = DescriptorSetLayout;
@@ -179,7 +169,6 @@ internal sealed unsafe class VulkanPipeline : IDisposable
                 sType = VkStructureType.PipelineRenderingCreateInfo,
                 colorAttachmentCount = 1,
                 pColorAttachmentFormats = &colorFormat,
-                depthAttachmentFormat = depthFormat,
             };
 
             var pipelineInfo = new VkGraphicsPipelineCreateInfo
@@ -193,7 +182,6 @@ internal sealed unsafe class VulkanPipeline : IDisposable
                 pViewportState = &viewportState,
                 pRasterizationState = &rasterizationState,
                 pMultisampleState = &multisampleState,
-                pDepthStencilState = &depthStencilState,
                 pColorBlendState = &colorBlendState,
                 pDynamicState = &dynamicState,
                 layout = PipelineLayout,