Implement playable Mac client and rendering validation

script/build_macos_release_engine.sh

@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+# Reproducible Metal-only release template used by the particle exit checks.
+# Does not replace Godot's installed templates. Pass the resulting executable
+# to build-macos-client.sh using MT_MAC_ENGINE and the matching MT_MAC_ARCHES.
+set -euo pipefail
+cd "$(dirname "$0")/.."
+repo_dir="$PWD"
+source_dir="$repo_dir/build/godot-particle-diagnostic"
+revision="a13da4feb8d8aefc283c3763d33a2f170a18d541"
+engine_arch="${1:-arm64}"
+case "$engine_arch" in arm64|x86_64) ;; *) echo "Expected arm64 or x86_64" >&2; exit 1 ;; esac
+if [ ! -d "$source_dir" ]; then
+  git clone --depth 1 --branch 4.7.1-stable https://github.com/godotengine/godot.git "$source_dir"
+fi
+test "$(git -C "$source_dir" rev-parse HEAD)" = "$revision"
+git -C "$source_dir" diff --exit-code
+git -C "$source_dir" diff --cached --exit-code
+cd "$source_dir"
+scons platform=macos arch="$engine_arch" target=template_release \
+  debug_symbols=yes optimize=speed lto=none vulkan=no -j8
+echo "Engine: $source_dir/bin/godot.macos.template_release.$engine_arch"
+shasum -a 256 "bin/godot.macos.template_release.$engine_arch"