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, 6 insertions, 31 deletions

diff --git a/src/gpu/gpu.cc b/src/gpu/gpu.cc
index 8342c94..1f71711 100644
--- a/src/gpu/gpu.cc
+++ b/src/gpu/gpu.cc
@@ -5,15 +5,13 @@
 #include "gpu.h"
 #include "demo_effects.h"
 #include "effect.h"
-#include "platform.h"
 #include "gpu/effects/shaders.h"
+#include "platform.h"
 
-#include <GLFW/glfw3.h>
-#include <math.h>
-
-#include <algorithm>
 #include <cassert>
+#include <cmath>
 #include <cstdint>
+#include <cstdio>
 #include <cstring>
 #include <vector>
 
@@ -21,29 +19,6 @@
 #include <iostream>
 #endif /* !defined(STRIP_ALL) */
 
-// --- WebGPU Headers & Compatibility ---
-#if defined(DEMO_CROSS_COMPILE_WIN32)
-// Renamed Types/Enums
-#define WGPUOptionalBool_False false
-#define WGPUSurfaceGetCurrentTextureStatus_SuccessOptimal                      \
-  WGPUSurfaceGetCurrentTextureStatus_Success
-#define WGPUSurfaceGetCurrentTextureStatus_SuccessSuboptimal                   \
-  WGPUSurfaceGetCurrentTextureStatus_Success
-#define WGPUCallbackMode_WaitAnyOnly 0
-static void wgpuInstanceWaitAny(WGPUInstance instance, size_t, void*,
-                                uint64_t) {
-  wgpuInstanceProcessEvents(instance);
-}
-static void set_error_callback(WGPUDevice device, WGPUErrorCallback callback) {
-  wgpuDeviceSetUncapturedErrorCallback(device, callback, nullptr);
-}
-#else
-static void set_error_callback(WGPUDevice device,
-                               WGPUUncapturedErrorCallback callback) {
-  // Handled in descriptor for new API.
-}
-#endif /* defined(DEMO_CROSS_COMPILE_WIN32) */
-
 static WGPUInstance g_instance = nullptr;
 static WGPUAdapter g_adapter = nullptr;
 static WGPUDevice g_device = nullptr;
@@ -331,7 +306,7 @@ void gpu_init(PlatformState* platform_state) {
   wgpuInstanceRequestAdapter(g_instance, &adapter_opts, adapter_cb);
 #endif /* defined(DEMO_CROSS_COMPILE_WIN32) */
   while (!g_adapter)
-    wgpuInstanceWaitAny(g_instance, 0, nullptr, 0);
+    platform_wgpu_wait_any(g_instance);
 
   WGPUDeviceDescriptor device_desc = {};
 #if !defined(STRIP_ALL)
@@ -351,10 +326,10 @@ void gpu_init(PlatformState* platform_state) {
   wgpuAdapterRequestDevice(g_adapter, &device_desc, device_cb);
 #endif /* defined(DEMO_CROSS_COMPILE_WIN32) */
   while (!g_device)
-    wgpuInstanceWaitAny(g_instance, 0, nullptr, 0);
+    platform_wgpu_wait_any(g_instance);
 
 #if defined(DEMO_CROSS_COMPILE_WIN32) && !defined(STRIP_ALL)
-  set_error_callback(g_device, handle_device_error);
+  platform_wgpu_set_error_callback(g_device, handle_device_error);
 #endif /* defined(DEMO_CROSS_COMPILE_WIN32) && !defined(STRIP_ALL) */
 
   g_queue = wgpuDeviceGetQueue(g_device);