refactor: Task #20 - Platform & Code Hygiene

- Consolidated all WebGPU shims and platform-specific logic into src/platform.h.
- Refactored platform_init to return PlatformState by value and platform_poll to automatically refresh time and aspect_ratio.
- Removed STL dependencies (std::map, std::vector, std::string) from AssetManager and Procedural subsystems.
- Fixed Windows cross-compilation by adjusting include paths and linker flags in CMakeLists.txt and updating build_win.sh.
- Removed redundant direct inclusions of GLFW/glfw3.h and WebGPU headers across the project.
- Applied clang-format and updated documentation.

handoff(Gemini): Completed Task #20 and 20.1. Platform abstraction is now unified, and core paths are STL-free. Windows build is stable.

1 files changed, 13 insertions, 32 deletions

diff --git a/src/tests/test_3d_render.cc b/src/tests/test_3d_render.cc
index cc7dce6..6e639cd 100644
--- a/src/tests/test_3d_render.cc
+++ b/src/tests/test_3d_render.cc
@@ -5,21 +5,15 @@
 #include "3d/object.h"
 #include "3d/renderer.h"
 #include "3d/scene.h"
-#include "gpu/texture_manager.h"
 #include "gpu/effects/shaders.h"
+#include "gpu/texture_manager.h"
 #include "platform.h"
 #include "procedural/generator.h"
 #include <cmath>
+#include <cstdio>
 #include <cstring>
-#include <iostream>
 #include <vector>
 
-#if defined(DEMO_CROSS_COMPILE_WIN32)
-#include <webgpu/webgpu.h>
-#else
-#include <webgpu.h>
-#endif
-
 // Global State
 static Renderer3D g_renderer;
 static TextureManager g_textures;
@@ -35,13 +29,13 @@ static WGPUTextureFormat g_format = WGPUTextureFormat_Undefined;
 void init_wgpu(PlatformState* platform_state) {
   WGPUInstance instance = wgpuCreateInstance(nullptr);
   if (!instance) {
-    std::cerr << "Failed to create WGPU instance." << std::endl;
+    fprintf(stderr, "Failed to create WGPU instance.\n");
     exit(1);
   }
 
   g_surface = platform_create_wgpu_surface(instance, platform_state);
   if (!g_surface) {
-    std::cerr << "Failed to create WGPU surface." << std::endl;
+    fprintf(stderr, "Failed to create WGPU surface.\n");
     exit(1);
   }
 
@@ -60,6 +54,7 @@ void init_wgpu(PlatformState* platform_state) {
 #else
   auto on_adapter = [](WGPURequestAdapterStatus status, WGPUAdapter adapter,
                        WGPUStringView message, void* userdata, void* user2) {
+    (void)user2;
     if (status == WGPURequestAdapterStatus_Success) {
       *(WGPUAdapter*)userdata = adapter;
     }
@@ -71,15 +66,8 @@ void init_wgpu(PlatformState* platform_state) {
   wgpuInstanceRequestAdapter(instance, &adapter_opts, adapter_cb);
 #endif
 
-#if !defined(DEMO_CROSS_COMPILE_WIN32)
   while (!g_adapter) {
-    wgpuInstanceProcessEvents(instance);
-  }
-#endif
-
-  if (!g_adapter) {
-    std::cerr << "Failed to get adapter." << std::endl;
-    exit(1);
+    platform_wgpu_wait_any(instance);
   }
 
   WGPUDeviceDescriptor device_desc = {};
@@ -95,6 +83,7 @@ void init_wgpu(PlatformState* platform_state) {
 #else
   auto on_device = [](WGPURequestDeviceStatus status, WGPUDevice device,
                       WGPUStringView message, void* userdata, void* user2) {
+    (void)user2;
     if (status == WGPURequestDeviceStatus_Success) {
       *(WGPUDevice*)userdata = device;
     }
@@ -106,15 +95,8 @@ void init_wgpu(PlatformState* platform_state) {
   wgpuAdapterRequestDevice(g_adapter, &device_desc, device_cb);
 #endif
 
-#if !defined(DEMO_CROSS_COMPILE_WIN32)
   while (!g_device) {
-    wgpuInstanceProcessEvents(instance);
-  }
-#endif
-
-  if (!g_device) {
-    std::cerr << "Failed to get device." << std::endl;
-    exit(1);
+    platform_wgpu_wait_any(instance);
   }
 
   g_queue = wgpuDeviceGetQueue(g_device);
@@ -206,8 +188,7 @@ int main(int argc, char** argv) {
   (void)argv;
 #endif
 
-  PlatformState platform_state = {};
-  platform_init(&platform_state, false, nullptr, nullptr);
+  PlatformState platform_state = platform_init(false, 1280, 720);
 
   // The test's own WGPU init sequence
   init_wgpu(&platform_state);
@@ -222,7 +203,8 @@ int main(int argc, char** argv) {
   noise_def.width = 256;
   noise_def.height = 256;
   noise_def.gen_func = gen_periodic_noise;
-  noise_def.params = {1234.0f, 16.0f};
+  noise_def.params.push_back(1234.0f);
+  noise_def.params.push_back(16.0f);
   g_textures.create_procedural_texture("noise", noise_def);
 
   g_renderer.set_noise_texture(g_textures.get_texture_view("noise"));
@@ -232,17 +214,16 @@ int main(int argc, char** argv) {
   g_camera.position = vec3(0, 5, 10);
   g_camera.target = vec3(0, 0, 0);
 
-  float time = 0.0f;
   while (!platform_should_close(&platform_state)) {
     platform_poll(&platform_state);
-    time = (float)platform_get_time();
+    float time = (float)platform_state.time;
 
     float cam_radius = 10.0f + std::sin(time * 0.3f) * 4.0f;
     float cam_height = 5.0f + std::cos(time * 0.4f) * 3.0f;
     g_camera.set_look_at(vec3(std::sin(time * 0.5f) * cam_radius, cam_height,
                               std::cos(time * 0.5f) * cam_radius),
                          vec3(0, 0, 0), vec3(0, 1, 0));
-    g_camera.aspect_ratio = platform_get_aspect_ratio(&platform_state);
+    g_camera.aspect_ratio = platform_state.aspect_ratio;
 
     for (size_t i = 1; i < g_scene.objects.size(); ++i) {
       // Rotation around a random-ish 3D axis