Fry3DX 0.4: an easy 3D modeller

Shapes with live settings, shape editing, knife and hole tools, drawing
shapes onto other objects, combining objects (add / subtract / overlap),
copies, thickness, painting with stickers and layers, a Layout tab, a
Print tab with checks, packed .fry files with autosave, export to GLB,
glTF, FBX, OBJ, 3MF, STL and PLY, folders in Layers, its own crash
screen, and a website for GitHub Pages in docs/.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NMSrd5oe1GpUD7E6d825KP

engine/render/screenshot.h

@@ -0,0 +1,11 @@
+#pragma once
+#include <cstdint>
+#include <string>
+#include <vector>
+
+namespace keel {
+// Writes RGBA8 pixels (row 0 at the top) to a PNG on a background thread; alpha is forced opaque.
+void saveScreenshot(std::string path, std::vector<uint8_t> rgba, uint32_t width, uint32_t height);
+// Blocks until screenshots still being written are done (before the process exits).
+void waitForScreenshots();
+} // namespace keel