Add GitHub Actions workflow to build Windows release DLLs

Uses the pre-installed Visual Studio 2022 Enterprise and vcpkg on

windows-latest runners. Installs protobuf for x86 and x64, generates

the protobuf C++ sources, then builds steam_api.dll and steam_api64.dll

and uploads them as artifacts.

Author: Roboman124

.github/workflows/build-windows.yml

@@ -0,0 +1,49 @@
+name: Build Windows Release
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+  workflow_dispatch:
+
+jobs:
+  build-windows:
+    runs-on: windows-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Install protobuf (x86 and x64)
+        shell: pwsh
+        run: |
+          $vcpkgRoot = $env:VCPKG_INSTALLATION_ROOT
+          & "$vcpkgRoot\bootstrap-vcpkg.bat"
+          & "$vcpkgRoot\vcpkg.exe" install protobuf:x86-windows-static protobuf:x64-windows-static
+
+      - name: Generate protobuf sources
+        shell: pwsh
+        run: |
+          $protoc = "$env:VCPKG_INSTALLATION_ROOT\packages\protobuf_x64-windows-static\tools\protobuf\protoc.exe"
+          & $protoc -I.\dll\ --cpp_out=.\dll\ .\dll\net.proto
+
+      - name: Build release DLLs
+        shell: cmd
+        run: |
+          call "C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Auxiliary\Build\vcvarsall.bat" x86
+          cl dll/rtlgenrandom.c dll/rtlgenrandom.def
+          cl /LD /DEMU_RELEASE_BUILD /DNDEBUG /I%VCPKG_INSTALLATION_ROOT%\packages\protobuf_x86-windows-static\include\ dll/*.cpp dll/*.cc %VCPKG_INSTALLATION_ROOT%\packages\protobuf_x86-windows-static\lib\libprotobuf-lite.lib Iphlpapi.lib Ws2_32.lib rtlgenrandom.lib Shell32.lib /EHsc /MP12 /Ox /link /debug:none /OUT:steam_api.dll
+          call "C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Auxiliary\Build\vcvarsall.bat" x64
+          cl dll/rtlgenrandom.c dll/rtlgenrandom.def
+          cl /LD /DEMU_RELEASE_BUILD /DNDEBUG /I%VCPKG_INSTALLATION_ROOT%\packages\protobuf_x64-windows-static\include\ dll/*.cpp dll/*.cc %VCPKG_INSTALLATION_ROOT%\packages\protobuf_x64-windows-static\lib\libprotobuf-lite.lib Iphlpapi.lib Ws2_32.lib rtlgenrandom.lib Shell32.lib /EHsc /MP12 /Ox /link /debug:none /OUT:steam_api64.dll
+
+      - name: Upload artifacts
+        uses: actions/upload-artifact@v4
+        with:
+          name: steam-api-dlls
+          path: |
+            steam_api.dll
+            steam_api64.dll
+            Readme_release.txt
+            files_example