Add RED4ext logging shim

tools/build_red4ext_shim.sh

@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+plugin_dir="$repo_root/red4ext/EdgeWeightGPS"
+build_dir="$repo_root/build/red4ext/EdgeWeightGPS-mingw64"
+sdk_dir="$repo_root/vendor/RED4ext.SDK"
+
+if [[ ! -f "$sdk_dir/include/RED4ext/Api/v1/PluginInfo.hpp" ]]; then
+  mkdir -p "$repo_root/vendor"
+  git clone --depth 1 https://github.com/WopsS/RED4ext.SDK.git "$sdk_dir"
+fi
+
+cmake -S "$plugin_dir" -B "$build_dir" \
+  -DCMAKE_TOOLCHAIN_FILE="$plugin_dir/cmake/mingw64-toolchain.cmake" \
+  -DCMAKE_BUILD_TYPE=RelWithDebInfo
+cmake --build "$build_dir" --parallel
+
+printf '%s\n' "$build_dir/EdgeWeightGPS.dll"