feat: MCP Unity 场景优化 — 完整交互体系搭建

- 删除重复 Ground
- 创建 [Managers] 空物体，挂载 GameManager + StepManager + ExperimentFlowCoordinator + AudioManager
- Main Camera 挂载 InteractionSystem
- 伤者 InjectedPerson 下创建 5 个交互子物体 (InjuryVisual/Swelling/Pain/VitalSigns/Neuro)
- 创建绑带位置、踝关节、衬垫、夹板位置等空物体
- 道具摆放到位：伤者(2,0.05,5) 施救者(3,0,5) 鞋(2.7,0.15,5.5) 绷带/夹板/急救箱在旁
- InjuryLeg Tag 修正，Ground Tag 修正
- 全部新脚本同步导入 (ExperimentTypes/StepData/ExperimentConfig/StepManager/GameManager/ExperimentFlowCoordinator/InteractionSystem/DraggableObject/HighlightEffect/UIManager/ExamPopup/ScoreDisplay/VideoController/AudioManager/CharacterAnimController/StepAnimationHandler)
- 旧脚本 (ExperimentController/ConfigLoader/AnimationController/HUDController/VideoPlayerController/PopupSystem/ModeSelectionUI) 全部兼容修复或 stub
- 编译通过，0 错误
- Canvas 挂载 UIManager

Assets/Settings/URP-Performant.asset

@@ -12,8 +12,8 @@ MonoBehaviour:
   m_Script: {fileID: 11500000, guid: bf2edee5c58d82540a51f03df9d42094, type: 3}
   m_Name: URP-Performant
   m_EditorClassIdentifier: 
-  k_AssetVersion: 9
-  k_AssetPreviousVersion: 9
+  k_AssetVersion: 11
+  k_AssetPreviousVersion: 11
   m_RendererType: 1
   m_RendererData: {fileID: 0}
   m_RendererDataList:
@@ -23,10 +23,16 @@ MonoBehaviour:
   m_RequireOpaqueTexture: 0
   m_OpaqueDownsampling: 1
   m_SupportsTerrainHoles: 1
-  m_StoreActionsOptimization: 0
   m_SupportsHDR: 0
+  m_HDRColorBufferPrecision: 0
   m_MSAA: 1
   m_RenderScale: 1
+  m_UpscalingFilter: 0
+  m_FsrOverrideSharpness: 0
+  m_FsrSharpness: 0.92
+  m_EnableLODCrossFade: 1
+  m_LODCrossFadeDitheringType: 1
+  m_ShEvalMode: 0
   m_MainLightRenderingMode: 1
   m_MainLightShadowsSupported: 0
   m_MainLightShadowmapResolution: 1024
@@ -47,23 +53,62 @@ MonoBehaviour:
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   m_ShadowDepthBias: 1
   m_ShadowNormalBias: 1
+  m_AnyShadowsSupported: 1
   m_SoftShadowsSupported: 0
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+  m_NumIterationsEnclosingSphere: 64
+  m_SoftShadowQuality: 2
   m_AdditionalLightsCookieResolution: 2048
   m_AdditionalLightsCookieFormat: 3
   m_UseSRPBatcher: 1
   m_SupportsDynamicBatching: 0
   m_MixedLightingSupported: 1
+  m_SupportsLightCookies: 1
   m_SupportsLightLayers: 0
   m_DebugLevel: 0
+  m_StoreActionsOptimization: 0
+  m_EnableRenderGraph: 0
   m_UseAdaptivePerformance: 1
   m_ColorGradingMode: 0
   m_ColorGradingLutSize: 16
   m_UseFastSRGBLinearConversion: 0
+  m_SupportDataDrivenLensFlare: 1
   m_ShadowType: 1
   m_LocalShadowsSupported: 0
   m_LocalShadowsAtlasResolution: 256
   m_MaxPixelLights: 0
   m_ShadowAtlasResolution: 256
-  m_ShaderVariantLogLevel: 0
   m_VolumeFrameworkUpdateMode: 0
+  m_Textures:
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+    bayerMatrixTex: {fileID: 2800000, guid: f9ee4ed84c1d10c49aabb9b210b0fc44, type: 3}
+  m_PrefilteringModeMainLightShadows: 1
+  m_PrefilteringModeAdditionalLight: 4
+  m_PrefilteringModeAdditionalLightShadows: 1
+  m_PrefilterXRKeywords: 0
+  m_PrefilteringModeForwardPlus: 1
+  m_PrefilteringModeDeferredRendering: 1
+  m_PrefilteringModeScreenSpaceOcclusion: 1
+  m_PrefilterDebugKeywords: 0
+  m_PrefilterWriteRenderingLayers: 0
+  m_PrefilterHDROutput: 0
+  m_PrefilterSSAODepthNormals: 0
+  m_PrefilterSSAOSourceDepthLow: 0
+  m_PrefilterSSAOSourceDepthMedium: 0
+  m_PrefilterSSAOSourceDepthHigh: 0
+  m_PrefilterSSAOInterleaved: 0
+  m_PrefilterSSAOBlueNoise: 0
+  m_PrefilterSSAOSampleCountLow: 0
+  m_PrefilterSSAOSampleCountMedium: 0
+  m_PrefilterSSAOSampleCountHigh: 0
+  m_PrefilterDBufferMRT1: 0
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+  m_PrefilterSoftShadows: 0
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+  m_ShaderVariantLogLevel: 0
   m_ShadowCascades: 0