Reorganize directory layout: editor panels/, grouped shaders, drop stale header

- App/editor: move 7 panels into panels/ (Editor core stays at root)
- shaders/: group into pbr/ post/ debug/ env/ (runtime load paths updated)
- Delete outdated duplicate Engine/src/Renderer/VulkanAssetUploader.h

shaders/env/ibl_brdf_lut.comp

@@ -0,0 +1,54 @@
+#version 450
+
+// IBL ④：BRDF 积分 LUT（2D，纯数学，与环境内容无关）。
+// (NdotV, roughness) → (F 缩放 A, F 偏置 B)：specular = prefiltered·(F·A + B)。
+// 与环境切换无关，但随生成链一起跑（GPU 亚毫秒级），省去跨环境缓存。
+
+#include "ibl_common.glsl"
+
+layout(local_size_x = 8, local_size_y = 8) in;
+
+layout(set = 0, binding = 0, rg16f) uniform restrict writeonly image2D outLut;
+
+const uint SAMPLES = 128;
+
+void main()
+{
+    ivec2 gid = ivec2(gl_GlobalInvocationID);
+    if (gid.x >= imageSize(outLut).x || gid.y >= imageSize(outLut).y) return;
+
+    vec2 uv = (vec2(gid) + 0.5) / vec2(imageSize(outLut));
+    float nDotV = uv.x;
+    float roughness = uv.y;
+
+    // V 在以 N 为 +Z 的切线空间里（积分只依赖这两角度）
+    vec3 V = vec3(sqrt(1.0 - nDotV * nDotV), 0.0, nDotV);
+    vec3 Nz = vec3(0.0, 0.0, 1.0);
+
+    float a = 0.0, b = 0.0;
+    float k = roughness * roughness * 0.5;   // IBL 版 Smith k
+
+    for (uint i = 0u; i < SAMPLES; ++i) {
+        vec3 H = iblImportanceSampleGGX(iblHammersley(i, SAMPLES), Nz, roughness);
+        vec3 L = normalize(2.0 * dot(V, H) * H - V);
+
+        float lDotN = L.z;
+        float nDotL = max(lDotN, 0.0);
+        float nDotH = max(H.z, 0.0);
+        float vDotH = max(dot(V, H), 0.0);
+        if (nDotL <= 0.0) continue;
+
+        float g = (nDotV / (nDotV * (1.0 - k) + k)) *
+                  (nDotL / (nDotL * (1.0 - k) + k));
+        // 高 roughness 时部分样本 H.z 恰为 0（g 也为 0），0/0 = NaN
+        // 会累进 LUT——分母钳 epsilon（与 CPU 版一致）
+        float gVis = g * vDotH / max(nDotH * nDotV, 1e-6);
+        float fc = 1.0 - vDotH;
+        float f = fc * fc * fc * fc * fc;   // (1-vDotH)⁵
+
+        a += (1.0 - f) * gVis;
+        b += f * gVis;
+    }
+
+    imageStore(outLut, gid, vec4(a / float(SAMPLES), b / float(SAMPLES), 0.0, 1.0));
+}