Improve PBR quality: mip chains, anisotropic filtering, baseColorFactor

Root causes behind blurry/unphysical materials (4K pocket watch render
mushy, glass fully opaque, watch hands unreadable):

- Textures loaded via stbi had a single mip level: 4096x4096 albedo/MR
  maps sampled with no LOD -> minification aliasing turned fine detail
  (watch hands) into noise. Generate a full blit-based mip chain with
  per-level layout transitions.
- samplerAnisotropy was never enabled on the device and every sampler
  was created with anisotropy disabled: grazing-angle surfaces (watch
  face, ground) collapsed into a blur. Enable the device feature and
  16x anisotropic filtering on material texture samplers.
- glTF baseColorFactor was ignored: the glass material (alphaMode
  BLEND, no baseColor texture, baseColorFactor.a = 0.3) fell back to
  the default white texture with alpha = 1 and rendered fully opaque.
  MaterialParams gains a baseColor vec4 (rgb tints albedo, a scales
  the blend alpha) threaded through both PBR shaders.
- alphaMode MASK was treated as opaque: add a factors.w switch that
  performs an alpha cutout test in the opaque shader.
- Fix material cache key dropping factors.z (separate-roughness
  switch); it now encodes the full factors and baseColor vectors.

Engine/include/Engine/Renderer/Material.h

@@ -43,7 +43,10 @@ namespace Engine {
     // x = metallic 因子  y = roughness 因子
     // z = 独立粗糙度图开关（1 = 用 Roughness 槽 R 通道替换 MR.g）
     struct MaterialParams {
+        // x = metallic 因子，y = roughness 因子，z = 独立粗糙度图开关，w = MASK 镂空开关
         glm::vec4 factors{0.0f, 0.5f, 0.0f, 0.0f};
+        // glTF baseColorFactor：rgb 乘进 albedo，a 作 BLEND 透明度
+        glm::vec4 baseColor{1.0f, 1.0f, 1.0f, 1.0f};
     };
 
     class Material {

Engine/include/Engine/Vulkan/Device.h

@@ -45,6 +45,9 @@ public:
     bool IsSynchronization2Supported() const { return m_Synchronization2Supported; }
     // MDI：drawCount>1 的 drawIndexedIndirect(Count) 必需（core 特性位）
     bool IsMultiDrawIndirectSupported() const { return m_MultiDrawIndirectSupported; }
+    // 各向异性过滤：纹理采样器清晰度（掠射角材质锐利度）的硬件开关
+    bool IsSamplerAnisotropySupported() const { return m_SamplerAnisotropySupported; }
+    float MaxSamplerAnisotropy() const { return m_MaxSamplerAnisotropy; }
 
 private:
     void CreateInstance();
@@ -76,6 +79,8 @@ private:
     bool m_Synchronization2Supported = false;
     bool m_MultiDrawIndirectSupported = false;
     bool m_DrawIndirectCountSupported = false;
+    bool m_SamplerAnisotropySupported = false;
+    float m_MaxSamplerAnisotropy = 1.0f;
 
     std::vector<const char*> m_ValidationLayers = { "VK_LAYER_KHRONOS_validation" };
     std::vector<const char*> m_DeviceExtensions = { VK_KHR_SWAPCHAIN_EXTENSION_NAME };

Engine/include/Engine/Vulkan/Texture.h

@@ -54,7 +54,8 @@ namespace Engine {
         Texture(Device& device, MemoryAllocator& allocator, ProceduralTag,
                 const std::array<u8, 4>& rgba, bool srgb);
 
-        // 公共路径：staging → device local image → view/sampler（RGBA8 单 mip）
+        // 公共路径：staging → device local image → blit 生成完整 mip 链 →
+        // view/sampler（RGBA8，各向异性过滤）
         void InitFromPixels(const void* pixels, u32 width, u32 height, bool srgb);
 
         // DDS 路径：压缩数据直传（BC 硬件采样解码）+ 文件自带 mip 链