refactor(gpu): Integrate WebGPU via system wgpu-native and glfw3webgpu

Replaces the complex wgpu-native submodule and manual platform-specific surface creation with a system-wide wgpu-native install (via Homebrew) and the glfw3webgpu helper library.

- Updates scripts/project_init.sh to fetch glfw3webgpu and ensure wgpu-native is installed.

- Refactors CMakeLists.txt to link against the system wgpu-native library.

- Simplifies src/platform.cc to use glfwCreateWindowWGPUSurface.

- Simplifies src/gpu/gpu.cc to use standard WebGPU headers.

- Updates FETCH_DEPS.md with new installation instructions.

- Updates PROJECT_CONTEXT.md with the new integration strategy.

1 files changed, 62 insertions, 0 deletions

diff --git a/third_party/glfw3webgpu/glfw3webgpu.h b/third_party/glfw3webgpu/glfw3webgpu.h
new file mode 100644
index 0000000..729afcc
--- /dev/null
+++ b/third_party/glfw3webgpu/glfw3webgpu.h
@@ -0,0 +1,62 @@
+/**
+ * This is an extension of GLFW for WebGPU, abstracting away the details of
+ * OS-specific operations.
+ * 
+ * This file is part of the "Learn WebGPU for C++" book.
+ *   https://eliemichel.github.io/LearnWebGPU
+ * 
+ * MIT License
+ * Copyright (c) 2022-2024 Elie Michel and the wgpu-native authors
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef _glfw3_webgpu_h_
+#define _glfw3_webgpu_h_
+
+#include <webgpu.h>
+#include <GLFW/glfw3.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*! @brief Creates a WebGPU surface for the specified window.
+ *
+ *  This function creates a WGPUSurface object for the specified window.
+ *
+ *  If the surface cannot be created, this function returns `NULL`.
+ *
+ *  It is the responsibility of the caller to destroy the window surface. The
+ *  window surface must be destroyed using `wgpuSurfaceRelease`.
+ *
+ *  @param[in] instance The WebGPU instance to create the surface in.
+ *  @param[in] window The window to create the surface for.
+ *  @return The handle of the surface.  This is set to `NULL` if an error
+ *  occurred.
+ *
+ *  @ingroup webgpu
+ */
+WGPUSurface glfwCreateWindowWGPUSurface(WGPUInstance instance, GLFWwindow* window);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _glfw3_webgpu_h_