请分析我上传的书桌照片中的物品布局（显示器、机械键盘、鼠标、台灯摆件）。以这些真实物品为地形障碍，生成一张具有强烈微缩模型玩具质感（Tilt-Shift Macro Photography）的 3D 赛车赛道概念图。
视觉要求：
1. 一辆鲜红色的微型卡丁车正在键盘前方疾驰，车身尺寸与单个机械键帽相仿。
2. 赛道是一条高架曲面轨道，配有红白相间的减速路缘与柔光防撞护栏，轻巧地从显示器支架下方穿过并环绕鼠标。
3. 灯光具有戏剧性对比：暗调房间背景，屏幕背后的深紫色氛围光，机械键盘缝隙透出的青色背光，以及桌面台灯投下的高对比暖白主光。
4. 整体呈现出精致小巧的微缩玩具世界视觉质感。

Analyze the desktop layout in the uploaded photos (monitor, mechanical keyboard, mouse, desk lamp). Using these real objects as miniature terrain obstacles, generate a 3D racing concept art with strong tilt-shift macro toy aesthetic.
Key requirements:
1. A vibrant red miniature go-kart racing in front of the keyboard, scaled proportionally to single keycaps.
2. An elevated curved track with red-and-white rumble strips and glowing barriers, looping under the monitor stand and around the mouse.
3. Dramatic lighting contrast: dim room ambience, deep purple backlight behind monitor, cyan glow between keycaps, and warm white key light from desk lamp.
4. Premium stylized game aesthetics reminiscent of a micro miniature toy universe.

请查看我上传的书桌照片与实测尺寸。以下以宽 1.2m、深 0.6m 为示例，先让我替换为自己的桌面和道具尺寸，缺少的尺寸向我确认。
因为本场景需要精确贴合物体间隙，请先不要生成任何 3D 网格代码：
1. **生成 2D 矢量平面图**：以米为单位，生成一份顶视图 2D 矢量图并保存至 `PLAN/layout.svg`，明确标注显示器底座、键盘、鼠标与边缘留白的绝对长宽与中心坐标（原点设在桌面几何中心）。
2. **叠加参考编号网格**：写一段轻量脚本或在 SVG 中绘制带编号的 X/Y 米制网格（间距 0.05m），标明计划中的闭环赛道走线与关键转弯控制点。
3. **空间通行检验**：检查键盘与显示器底座之间的预留间隙是否大于赛道宽度（0.08m），确认无阻挡后再输出坐标总结。
完成上述 2D 尺寸验证后，我们再依据这些已锁定的绝对坐标构建 3D 几何网格。

Review my desk photos and measured dimensions. The example tabletop is 1.2m wide and 0.6m deep; ask me to replace these and supply the measured prop sizes before fixing coordinates.
Since this build requires spatial accuracy, do NOT generate any 3D meshes yet:
1. **Generate 2D Vector Plan**: Create a top-down 2D floorplan in metric units and save it to `PLAN/layout.svg`. Map out the exact bounding boxes and center coordinates for the monitor base, keyboard, mouse, and margins (origin at desk center).
2. **Numbered Reference Grid**: Overlay a numbered X/Y metric grid (0.05m spacing) across the layout, plotting the planned closed track loop and key spline control points.
3. **Clearance Verification**: Verify that the gap between the keyboard and monitor base exceeds the road width (0.08m) without collisions before outputting coordinate tables.
Once we verify these 2D spatial dimensions, we will use these locked coordinates to build the 3D scene.

/grill-me 我们将在当前 `desk-racer` 项目中，基于我上传的书桌照片构建一款 3D 网页微缩卡丁车赛车游戏。
请注意：此时请不要编写任何 3D 代码。

请按以下顺序执行：
1. **需求反向盘问**：向我提出关于操控手感（街机 vs 模拟）、光影氛围与桌面道具处理方式的关键澄清问题。
2. **概念图确认**：优先使用我已选中的 Nano Banana 概念图；如尚未确定，则生成赛道走线与关键道具的候选图，在对话中供我确认。你的最终 3D 制作目标是尽可能精确还原这组概念图的风格与布局。在得到我的明确确认前，不要进入编码阶段。
3. **制定计划与生成 /goal**：在我确认概念图并回答问题后，编写包含清晰里程碑的完整 `PLAN.md`，并为我提供一条可以直接执行的 `/goal` 指令，用于启动长时间自主构建循环。

若当前环境支持子 Agent，请将场景道具（Props）、材质贴图（Texture）与灯光交互（Lighting）拆分为并行子角色；若不支持则按阶段顺序执行。
核心交付标准：
- 模块化架构：Three.js + Vite，拆分 `main.js`、`track.js`、`car.js`、`lights.js` 与 `props.js`。
- 控制与机位：W/A/S/D 驾驶操作，数字键 1~4 平滑切换机位。
- 资产与碰撞：通过 Blender MCP 导出 `public/models/desk-props.glb` 并在网页中加载，带状高架赛道具备防止穿模掉落的碰撞体与接地支柱。

/grill-me Help me plan a miniature browser kart racer based on my desk photos in the `desk-racer` workspace. Hold off on generating 3D code until we agree on the design.
1. Ask about driving feel, camera modes, lighting, and which objects need custom models.
2. Use the Nano Banana concept I have already selected. If none is selected, produce track and prop concepts and show them in chat. Wait for my choice before coding.
3. After I answer the questions and confirm a concept, save a milestone-based plan as `PLAN.md` and propose an executable `/goal` instruction for completing it.
Delegate props, textures, and lighting where subagents are supported; otherwise work through these milestones in sequence.
Deliver a Vite + Three.js project organized into `main.js`, `track.js`, `car.js`, `lights.js`, and `props.js`. Include WASD driving, four smooth camera modes, Blender props exported to `public/models/desk-props.glb`, and an elevated ribbon track with grounded supports and collision boundaries.

请在当前 `desk-racer` 前端项目中创建首个完整的可玩原型代码。请直接生成以下文件：
1. `index.html`：标准 HTML5 页面，设置全屏无边距样式，引入 `#app` 容器，引入 `/src/main.js` 作为 ES 模块。
2. `src/main.js`：Three.js 主入口。初始化场景、透视摄像机（FOV 60，near 0.02，far 50）、WebGLRenderer（开启阴影与抗锯齿），窗口 resize 动态适配监听。
3. `src/car.js`：白模赛车类。用简单长方体组装赛车车身（红底白顶，尺寸约 0.05m × 0.025m × 0.02m）。实现基于前进速度、角速度与摩擦力阻尼的刚体移动逻辑。监听键盘按键：W 加速、S 刹车与倒车、A/D 左右转向、R 键重置位置与航向。
4. `src/track.js`：基础闭环赛道。生成一条平整的带状赛道网格（Ribbon Mesh，道路宽度 0.08m，厚度 0.005m），环绕桌面中心形成连续闭环曲面，带有简易发车线与红白路缘涂装。
5. `src/camera.js`：摄像机系统。支持 4 组视角平滑跟随切换：按键 1（后方跟车）、按键 2（引擎盖座舱）、按键 3（桌面全景俯瞰）、按键 4（轨道慢速漫游）。
6. `src/lights.js`：基础光源。提供一盏桌面主聚光灯（投射阴影）与一盏暗调环境光。

生成完毕后，请检查代码结构无语法错误，确保无需额外依赖即可直接导入运行。

Please scaffold the first playable prototype in the current `desk-racer` project by creating the following files:
1. `index.html`: Standard HTML5 boilerplate, reset CSS for fullscreen canvas, `#app` mount container, importing `/src/main.js` as an ES module.
2. `src/main.js`: Main Three.js entry point. Set up scene, perspective camera (FOV 60, near 0.02, far 50), WebGLRenderer with shadows and antialiasing enabled, and a responsive resize handler.
3. `src/car.js`: Whitebox vehicle class. Construct a modular box car (red body, white roof, ~0.05m × 0.025m × 0.02m). Implement basic arcade physics with acceleration, steering yaw, braking, and damping. Bind key inputs: W (throttle), S (brake/reverse), A/D (steer), R (reset position and rotation).
4. `src/track.js`: Basic closed ribbon track. Build a flat drivable ribbon road mesh (width 0.08m, thickness 0.005m) forming a continuous loop around the desk center, complete with a checkered start line and red/white curb striping.
5. `src/camera.js`: Multi-camera rig. Implement smooth lerped switching across 4 modes: Key 1 (Chase Cam), Key 2 (Hood/Cockpit Cam), Key 3 (Top-down Overview), Key 4 (Orbiting Drone).
6. `src/lights.js`: Initial lighting. Add a shadow-casting spotlight and dim ambient light.

Verify clean module exports and syntax correctness so the project runs immediately upon server start.

启动 `npx vite` 后，浏览器打开控制台出现了运行异常（如页面白屏、未找到 `#app`、Three.js 模块导入错误或着色器报错）。
请按以下步骤检查并修正代码：
1. 确认 `index.html` 中是否正确包含了 `<div id="app"></div>` 与 `<script type="module" src="/src/main.js"></script>`。
2. 检查 `src/main.js` 与各子模块的 `import` 路径是否正确使用了相对路径 `./car.js`、`./track.js` 等。
3. 检查渲染循环 `requestAnimationFrame` 中是否正确更新了车辆位置与摄像机插值变换。
4. 给出排查结论并直接提供修改后的文件内容。

Upon running `npx vite`, the browser console reports an error (blank screen, missing `#app` container, module resolution failure, or WebGL context error).
Please inspect and patch the codebase according to these checkpoints:
1. Verify `index.html` contains `<div id="app"></div>` and `<script type="module" src="/src/main.js"></script>`.
2. Ensure all module imports in `src/main.js` use proper relative specifiers (e.g., `./car.js`, `./track.js`).
3. Ensure the `requestAnimationFrame` render loop actively updates car kinematics and camera lerp transformations each frame.
4. State the root cause and provide patched code files directly.

请调用本地 Blender MCP 服务的 `execute_blender_code` 工具，执行 Python 脚本为我的赛车游戏生成一套低多边形（Low-Poly）桌面障碍道具：
1. **物体位置与尺寸规划（以米为单位，示例数据可根据实测替换）**：
   - **机械键盘（Keyboard）**：位置 `(0, 0.01, 0.12)`，基座尺寸约 0.36m × 0.14m × 0.02m，表面排列简化的键帽阵列，赋予深灰哑光材质。
   - **显示器底座与支架（Monitor）**：位置 `(0, 0, -0.22)`，扁平底座配垂直支架，上方悬挂屏幕面板（0.55m × 0.32m），屏幕表面赋予深色反光材质。
   - **鼠标（Mouse）**：位置 `(0.24, 0.015, 0.12)`，流线型圆角网格，长约 0.11m、宽 0.06m。
2. **组织与坐标规范**：保持各物体独立名称（`Keyboard`、`Monitor`、`Mouse`），不合并为单个重叠几何体。上面的示例位置采用 Three.js 的 Y 轴向上坐标；写 Blender 脚本时，将 (x,y,z) 映射为 (x,-z,y)，以 Blender Z=0 对应桌面。
3. **导出要求**：使用当前项目工程的绝对输出路径，将上述模型组合以二进制 GLB 格式导出至当前项目的 `public/models/desk-props.glb` 文件中。
4. **完成检查**：脚本执行后，请检查导出文件在磁盘上是否存在且大小大于 0 字节，并汇报各个物体的最终世界坐标。

Please invoke `execute_blender_code` via local Blender MCP to generate low-poly desktop props with independent world coordinates using Python:
1. **Layout & Dimensions (meters, adjustable defaults)**:
   - **Keyboard**: Center `(0, 0.01, 0.12)`, base ~0.36m × 0.14m × 0.02m with simplified keycap array, matte dark plastic material.
   - **Monitor**: Center `(0, 0, -0.22)`, thin rectangular base, upright riser, widescreen bezel (0.55m × 0.32m) with glossy dark glass material.
   - **Mouse**: Center `(0.24, 0.015, 0.12)`, ergonomic low-poly contour (~0.11m × 0.06m).
2. **Scene Hierarchy**: Keep distinct object names (`Keyboard`, `Monitor`, `Mouse`) without collapsing all meshes onto origin. The listed coordinates use Three.js Y-up; map (x,y,z) to Blender (x,-z,y), with Blender Z=0 as the tabletop.
3. **Export Specification**: Use the project's absolute filesystem path to export the props collection as binary GLB directly to `public/models/desk-props.glb`.
4. **Verification**: Confirm file existence on disk, verify file size is greater than 0 bytes, and output the final object transform coordinates.

请在 `src/track.js` 中构建一套环绕桌面物体的闭环带状高架赛道系统：
1. **几何形状**：基于三维样条曲线（`CatmullRomCurve3`）生成闭环带状网格（宽 0.08m，厚 0.004m）。控制点走线避开键盘中心高耸区域，在键盘边缘抬升并从显示器前掠过。
2. **表面重叠防闪烁**：赛道整体最低处抬离桌面至少 0.003m，避免与桌面共面产生 Z-fighting 闪烁。
3. **支撑立柱**：沿高架赛道下沿均匀生成圆柱形支撑柱。每根支柱通过垂直向下射线检测（Raycaster）获取桌面上方实际落点，使支柱牢固连接轨道与桌面表面。
4. **规则与计时**：在赛道上设置起点线（Checkered Finish Line），实现 3 圈计时逻辑、当前圈速与最佳圈速显示、反向逆行警告与归位重置功能。
5. **分层碰撞**：在立体交叉路段，根据车辆当前高度匹配对应层级的赛道碰撞代理，防止赛车从上层立交桥意外吸附或坠落至下层路面。
编写完成后，请在浏览器中驾驶一圈，确认赛车能平稳通过所有弯道与高架桥。

Please develop an elevated closed ribbon track in `src/track.js` that navigates around desktop obstacles:
1. **Geometry**: Build a closed ribbon road mesh (width 0.08m, thickness 0.004m) driven by a 3D CatmullRom spline. Route control points to elevate over keyboard edges and dip gently near the monitor base.
2. **Coplanar Anti-Z-Fighting**: Offset track elevation at least 0.003m above tabletop surfaces to prevent depth-buffer fighting artifacts.
3. **Support Pillars**: Distribute vertical cylindrical pillars under elevated spans. Use downward raycasting against desk meshes to clamp each pillar base securely onto supporting surfaces.
4. **Lap Rules**: Add a checkered start/finish threshold, a 3-lap countdown timer, current/best lap tracking, wrong-way detection, and an instant reset trigger (`R` key).
5. **Layered Collision Handling**: Implement height-gated collision matching at overpass intersections so the vehicle does not snap onto underlying road segments.
Drive a complete test lap in the browser to ensure smooth cornering across elevated bridges.

请对 `src/car.js` 与 `src/camera.js` 执行比例优化，将赛车模型比例从 1:87 调整至 1:150 微缩规格：
1. **车体尺寸与碰撞体**：读取当前车体边界，按原尺寸的 87/150 等比缩小一次；碰撞包围盒和车轮离地检测距离同样乘 87/150，记录修改前后尺寸。
2. **跟随镜头偏移**：机位 1 的相对偏移向量和机位 2 的车体局部坐标都乘 87/150；保持 FOV 不变，比较前后截图中的赛车屏幕占比。
3. **裁剪面适配**：在 `src/main.js` 中将摄像机 `camera.near` 设置为 `0.01`，防止特写机位切除赛车网格。
4. **速度参数适配**：微调最大前进速度（约 0.8 m/s）与转向角速度，避免缩小车身后速度显得过快、难以控制。
请通过截屏检查赛车贴近按键时的画面构图与驾驶手感。

Please refine scale parameters across `src/car.js` and `src/camera.js`, adapting the vehicle from 1:87 down to 1:150 micro scale:
1. **Vehicle & Colliders**: Read the current bounds and multiply vehicle dimensions, collision bounds, and ground-check distances by 87/150 exactly once. Record before/after dimensions.
2. **Camera Offsets**: Multiply the chase-camera offset vector and cockpit local coordinates by 87/150. Keep FOV fixed and compare vehicle screen occupancy before/after.
3. **Near Clipping**: In `src/main.js`, configure `camera.near = 0.01` to prevent clipping artifacts during tight macro shots.
4. **Kinematic Tuning**: Recalibrate top speed (~0.8 m/s) and turn rates to ensure realistic acceleration without visual teleportation at micro scales.
Verify visual framing against keycaps and validate handling responsiveness via test screenshots.

请在 `src/textures.js` 中创建纹理加载模块，并为游戏对象分配真实的 PBR 材质：
1. **贴图路径**：先从 `/textures/desk_wood.png` 和 `/textures/track_asphalt.png` 加载已保存的无缝颜色贴图，并按颜色图设置 sRGB。粗糙度贴图、法线贴图与金属贴图仅在文件真实存在时加载；没有时先用材质数值，不添加无效路径。
2. **纹理重复与包裹**：为贴图设置 `wrapS = wrapT = THREE.RepeatWrapping`，针对长条赛道适当设置重复采样频率（如沿走向重复 40 次），防止贴图被严重拉伸变形。
3. **材质参数**：
   - 桌面：`MeshStandardMaterial`，赋予深棕木色，粗糙度 0.65，微弱镜面反射。
   - 赛道：深灰沥青质感，粗糙度 0.8；若已有正确法线贴图，再加入颗粒细节。
   - 赛车：高光红色烤漆，粗糙度 0.25，金属度 0.4。
导出 `applyMaterials(scene)` 函数并在 `src/main.js` 中调用。

Please implement a texture loading module in `src/textures.js` to assign PBR materials across scene meshes:
1. **Asset Paths**: Load the saved color textures `/textures/desk_wood.png` and `/textures/track_asphalt.png` with sRGB color space. Load roughness, normal, or metal maps only when their files exist; otherwise use material values and avoid missing URLs.
2. **Wrapping & Repeat**: Configure `wrapS = wrapT = THREE.RepeatWrapping`. Adjust UV repetition along the elongated track mesh (e.g., repeat 40 times longitudinally) to eliminate pixel stretching.
3. **Material Tuning**:
   - Tabletop: `MeshStandardMaterial`, warm walnut tint, roughness: 0.65, subtle specular sheen.
   - Track: Charcoal asphalt, roughness: 0.8; add normal detail only when a valid map is available.
   - Go-kart: Glossy racing red coat, roughness: 0.25, metalness: 0.4.
Export `applyMaterials(scene)` and hook it into `src/main.js`.

请在 `src/lights.js` 中完善三层复合光源系统，并在页面中添加调试控制面板与进度记录画廊：
1. **光源组织**：
   - 主台灯：`THREE.SpotLight`（暖黄色 `#fff4e0`，强度 2.5，投射阴影，设置合理 shadow.camera 范围）。
   - 显示器环境光：`THREE.PointLight`（深紫色 `#6b21a8`，强度 1.2，置于显示器背面）。
   - 键盘缝隙氛围：低强度点光源或自发光材质（青色 `#06b6d4`）。
2. **进度画廊（`progress.html`）**：每个开发里程碑完成后，自动捕获 4 张关键截图（全景、细节特写、贴地低视角、线框图），保存至 `public/progress/` 并在 `progress.html` 中以时间线展示，明确标注版本号与生成时间。
3. **交互调试面板与真实剪贴板复制**：在页面右上角添加轻量级控制面板（主灯强度、聚光角度、阴影 bias、色温、曝光度）。面板底部提供「复制 JSON 配置」按钮，点击时调用 `navigator.clipboard.writeText(JSON.stringify(config, null, 2))` 将当前参数真正复制到剪贴板（而非仅仅控制台打印）。
4. **配置固化**：提供明确的使用流程：当我把调优后的 JSON 粘贴回对话时，直接将其更新为 `src/lights.js` 中的默认参数，并在成片录制前提供隐藏或移除面板的开关。

Please build a composite three-tier lighting setup, an interactive debug GUI, and a progress gallery in `src/lights.js`:
1. **Hierarchy**:
   - Desk Spotlight: `THREE.SpotLight` (warm tone `#fff4e0`, intensity: 2.5, castShadow: true, properly bounded shadow camera frustum).
   - Monitor Rim Light: `THREE.PointLight` (deep violet `#6b21a8`, intensity: 1.2, placed behind monitor panel).
   - Keyboard Glow: Cyan accent point light (`#06b6d4`) or material emissive highlights.
2. **Progress Gallery (`progress.html`)**: After each milestone, capture 4 viewport screenshots (overview, detail close-up, low-angle ground check, wireframe view) into `public/progress/` and index them in `progress.html` with version numbers and timestamps.
3. **Interactive GUI & Real Clipboard Copy**: Embed lightweight on-screen sliders for spot intensity, penumbra, shadow bias, exposure, and color. Add a "Copy Settings as JSON" button that invokes `navigator.clipboard.writeText(JSON.stringify(config, null, 2))` to truly copy active settings to the system clipboard (not just console.log).
4. **Bake Defaults**: Establish a clear workflow: once I paste back the exported JSON, bake those values into `src/lights.js` as permanent defaults, and provide a toggle to hide or remove the debug GUI before final recording.

请启动一轮独立的对抗性艺术总监批评家（Adversarial Visual Critic）子智能体评审流程：
1. **渲染 4 组检查截图**：
   - 3/4 俯视全景：展示整体空间构图与赛道走向。
   - 局部特写：检查键盘键帽与沥青表面纹理。
   - 贴地低机位：检查赛车与支柱接地情况，确保无悬空漂浮。
   - 几何线框图：检查 3D 拓扑结构与潜在穿模点。
2. **严苛挑刺清单**：请批评家子 Agent 审查全部 4 张截图，列出实际发现的具体视觉缺陷（如高光泛白过曝、阴影边缘锯齿断裂、模型浮空或材质平淡），并给出修改意见。
3. **定位修复与停止依据**：
   - 定位至 `src/lights.js`、`src/textures.js` 或 `src/track.js` 执行代码修改。
   - 重新捕获截图进行复验。未发现问题时不要凑数。画面符合已确认的概念方向，赛车可跑完全程、机位平滑、资源加载无报错后结束本轮。

Please invoke an independent Adversarial Visual Critic subagent review pass for the current scene:
1. **Render 4 Verification Screenshots**:
   - 3/4 Overview: Demonstrating overall layout and track composition.
   - Close-up: Inspecting keycap textures and asphalt grain.
   - Low Angle: Inspecting vehicle contact and pillar bases to eradicate floating objects.
   - Wireframe View: Verifying clean 3D topology and potential collision intersections.
2. **Defect List**: Have the Critic subagent inspect all 4 screenshots, itemizing the visual flaws actually present (e.g., specular blowouts, shadow acne/detachment, floating meshes, or flat materials) with targeted remediation advice.
3. **Targeted Patching & Exit Criteria**:
   - Apply fixes directly across `src/lights.js`, `src/textures.js`, or `src/track.js`.
   - Re-capture screenshots for verification. Do not invent defects once they are fixed. End the round when the image matches our approved direction and multi-lap driving, camera modes, and asset loading pass.

隐藏 UI 按钮、调试滑块与 HUD，在当前项目的 3~5 个关键机位各保存一张清晰的 3D 截图，注明机位和版本。
将每张截图交给 Nano Banana 生成 2K 目标图：提升自然光照、桌面木纹、路面质感、反光与空间层次，保持原始相机视角、构图和物体布局。
按机位保存原截图与目标图，并把实际文件路径和预览发给我。若布局发生变化，重新生成后再进入代码修改。

Switch off the interface buttons, debug GUI, and HUD. Save clear screenshots from 3–5 useful camera positions, labeling the camera and revision.
For each view, ask Nano Banana for a 2K reference image with improved lighting, desk grain, road texture, reflections, and depth. Preserve the camera framing and object arrangement.
Save each source/reference pair and show me previews with their actual paths. Regenerate references that alter the layout before changing the game code.

对照同机位的当前 Three.js 截图与已确认的 Nano Banana 2K 目标图，列出阴影、桌面木纹、车身反光和背景暗部的具体差异。
根据差异修改现有项目的几何体、材质和灯光，定位 src/lights.js、src/textures.js、src/main.js 或实际使用的模型文件。
不要把目标图贴成平面背景。完成后在原机位重新截图，并旋转镜头、驾驶一圈，确认效果在实时 3D 中成立。将改动和前后画面发给我。

Use matching camera views to compare our live Three.js captures with the approved Nano Banana 2K references. Identify differences in shadows, wood grain, kart reflections, and the darker background.
Update the existing geometry, materials, and lights in src/lights.js, src/textures.js, src/main.js, or the model files actually used by this project.
Keep the reference image out of the scene background. Capture the original views again, rotate the camera, and drive a lap to confirm the improvement survives in real-time 3D. Show the edits and before/after captures.

请对当前 `desk-racer` 前端渲染性能执行指标测量与针对性优化：
1. **指标检测**：在页面中引入轻量性能监控器，实时显示当前 FPS、每帧时间 ms 与 `renderer.info.render.calls`（绘制调用次数）。
2. **排查瓶颈与光源减负**：测量主要开销属于 CPU 绘制调用瓶颈还是 GPU 填充率/阴影瓶颈。确保场景中仅保留 1 盏主聚光灯开启 `castShadow = true`，禁用显示器环境光的额外阴影通道。
3. **静态网格合并**：检查机械键盘模型。如果键帽由大量单独网格构成，请将其合并或转换为 `InstancedMesh`，对比合并前后的 DrawCalls 测量数值。
4. **运行验收**：在浏览器中连续跑圈测试，以 30fps 作为平稳运行的体验基准（在独立显卡上向 60fps 调优），消除急转弯与视角切换时的掉帧卡顿。

Please profile rendering performance for `desk-racer` and apply targeted optimizations:
1. **Telemetry**: Add a lightweight stats overlay tracking FPS, frame delta (ms), and `renderer.info.render.calls` (DrawCalls).
2. **Bottleneck Audit & Shadow Pruning**: Determine whether performance is bounded by CPU DrawCalls or GPU fill-rate/shadow passes. Ensure strictly ONE primary spotlight casts dynamic shadows; disable shadow casting on auxiliary monitor fill lights.
3. **Mesh Merging**: Inspect keyboard keycaps. If composed of dozens of individual meshes, batch them via `BufferGeometryUtils.mergeGeometries` or `InstancedMesh`, comparing DrawCall measurements before and after.
4. **Acceptance Test**: Run a continuous multi-lap driving benchmark to verify smooth performance above the 30fps baseline (targeting 60fps on capable GPUs) without stutter during high-speed cornering.

请在 `src/camera.js` 中实现平滑的摄像机控制器，支持按键 1、2、3、4 在不同视角间平滑插值过渡（使用 Vector3.lerp 与 Quaternion.slerp）：
1. **键 1 - 跟车视角**：目标位置位于赛车后方 0.08m、上方 0.035m，注视点朝向赛车前方 0.05m 处。
2. **键 2 - 座舱第一人称**：目标位置固定在赛车前罩上方 0.008m，注视正前方。
3. **键 3 - 桌面全景俯瞰**：固定在桌面中心上方 0.8m、斜侧 0.5m 处，静态俯视整张书桌。
4. **键 4 - 无人机环绕**：以桌面中心为圆心，按 0.15 rad/s 的角速度缓慢自转巡航。
确保切换视角时画面不会产生瞬间生硬瞬移，过渡平滑度在 0.6~0.8 秒左右完成。

Implement a smooth camera controller in `src/camera.js` supporting keys 1, 2, 3, 4 with lerped transitions (Vector3.lerp and Quaternion.slerp):
1. **Key 1 - Chase Cam**: Offset 0.08m behind, 0.035m above the vehicle, looking 0.05m ahead.
2. **Key 2 - Cockpit View**: Mounted directly 0.008m above vehicle hood, looking straight forward.
3. **Key 3 - Overview**: Stationary vantage point 0.8m above and 0.5m offset from desk center, overlooking the track.
4. **Key 4 - Orbit Drone**: Slow orbit around desk center at 0.15 rad/s.
Smooth transitions across states within ~0.6–0.8s without sudden position snaps.