feat: Shadow pass 接入 RenderGraph，支持 SRT 变换与程序化平面

阴影（本修正的核心根因）：
- Shadow pass 光源正交写深度（2048 D32），Forward 采样比较；
  写入与采样共用同一 lightSpace 矩阵，杜绝姿态/镜像不一致
- 修复：push constant range 64B→128B（原 Shadow pass 推 {lightVP,model}
  超出 layout 声明范围 = UB，阴影中模型矩阵读到垃圾导致旋转错乱）
- 修复：ShadowFactor 缺少 NDC→UV 映射（*0.5+0.5），采样区域整体错位
- 修复：RG ShaderRead stage 位值直转（eFragment=0x10 在 PipelineStage2
  是 TESSELLATION_CONTROL），改为逐位显式映射
- Camera perspective 深度重映射到 Vulkan [0,1]（公式与 ortho 不同：
  M22=M22*0.5-0.5, M32*=0.5）；光源 ortho remap 用 M32=M32*0.5+0.5

引擎配套：
- TransformComponent 重构为 position/rotation/scale + Compose()
- Texture::CreateSolidColor / Model::CreatePlane 程序化资产
  （两段式上传公共路径），AssetManager.CreatePlane 带缓存入口
- RG 新增 GetPhysicalView(h, slot)：按帧槽位把 RG 资源绑进外部描述符
  （阴影图 per-slot 物理镜像各自绑定）

验证：validation 0 error 0 warning，阴影随实体旋转正确

Engine/src/RenderGraph/RenderGraph.cpp

@@ -562,6 +562,17 @@ namespace Engine::RG {
         return img.release();
     }
 
+    vk::ImageView RenderGraph::GetPhysicalView(TextureHandle h, u32 frameSlot) const
+    {
+        const auto& entry = GetEntry(h);
+        if (entry.imported) return entry.importedView;
+        if (frameSlot >= entry.physical.size() || !entry.physical[frameSlot]) {
+            ENGINE_FATAL("RenderGraph: no physical image for '{}' slot {} "
+                         "(compile first?)", entry.name, frameSlot);
+        }
+        return entry.physical[frameSlot]->view;
+    }
+
     // ---------- 执行 ----------
 
     void RenderGraph::Execute(const FrameContext& frame)
@@ -679,11 +690,28 @@ namespace Engine::RG {
             case ResourceUse::DepthAttachment:
                 return vk::PipelineStageFlagBits2::eEarlyFragmentTests |
                        vk::PipelineStageFlagBits2::eLateFragmentTests;
-            case ResourceUse::ShaderRead:
-                // ShaderStageFlags 与 PipelineStageFlags2 位值兼容，需显式转换
-                return vk::PipelineStageFlags2(
-                    static_cast<VkPipelineStageFlags2>(
-                        static_cast<VkShaderStageFlags>(use.readStage)));
+            case ResourceUse::ShaderRead: {
+                // ShaderStageFlags 与 PipelineStageFlags2 位值不同
+                //（eFragment=0x10 vs eFragmentShader=0x80），禁止位值直转，逐位映射
+                vk::PipelineStageFlags2 mapped{};
+                if (use.readStage & vk::ShaderStageFlagBits::eVertex)
+                    mapped |= vk::PipelineStageFlagBits2::eVertexShader;
+                if (use.readStage & vk::ShaderStageFlagBits::eFragment)
+                    mapped |= vk::PipelineStageFlagBits2::eFragmentShader;
+                if (use.readStage & vk::ShaderStageFlagBits::eCompute)
+                    mapped |= vk::PipelineStageFlagBits2::eComputeShader;
+                if (use.readStage & vk::ShaderStageFlagBits::eGeometry)
+                    mapped |= vk::PipelineStageFlagBits2::eGeometryShader;
+                if (use.readStage & vk::ShaderStageFlagBits::eTessellationControl)
+                    mapped |= vk::PipelineStageFlagBits2::eTessellationControlShader;
+                if (use.readStage & vk::ShaderStageFlagBits::eTessellationEvaluation)
+                    mapped |= vk::PipelineStageFlagBits2::eTessellationEvaluationShader;
+                if (!mapped) {
+                    ENGINE_FATAL("RenderGraph: ShaderRead stage not mappable: {}",
+                                 static_cast<u32>(use.readStage));
+                }
+                return mapped;
+            }
             case ResourceUse::TransferSrc:
             case ResourceUse::TransferDst:
                 return vk::PipelineStageFlagBits2::eTransfer;