chore(cmake): add vcpkg overlay support for SDL2

- Introduced custom vcpkg port overlays to address SDL2 installation issues on Windows by skipping pkgconfig fixup.
- Updated CI and release workflows to include the new `VCPKG_OVERLAY_PORTS` configuration for enhanced build reliability.
- Added documentation for the overlays, detailing their purpose and usage.

Benefits:
- Prevents build failures related to SDL2 on Windows, improving the overall stability of the build process.
- Streamlines the integration of patched ports without forking the vcpkg repository, enhancing maintainability.

cmake/overlays/README.md

@@ -0,0 +1,37 @@
+# vcpkg Port Overlays
+
+This directory contains custom vcpkg port overlays that modify the behavior of specific packages during installation.
+
+## Purpose
+
+vcpkg overlays allow us to patch specific ports without forking the entire vcpkg repository. These overlays are automatically used when `VCPKG_OVERLAY_PORTS` is set in the CMake configuration.
+
+## Current Overlays
+
+### sdl2/
+
+**Problem**: The official SDL2 vcpkg port runs `vcpkg_fixup_pkgconfig()` on Windows, which attempts to download `pkgconf` from MSYS2 mirrors. These URLs frequently return 404 errors, causing build failures.
+
+**Solution**: Patched portfile that skips pkgconfig fixup on Windows platforms while maintaining it for Linux/macOS where it's needed.
+
+**Impact**: Prevents SDL2 installation failures on Windows without affecting functionality (pkgconfig isn't needed for Windows static builds).
+
+## Usage
+
+The overlays are automatically applied via the GitHub Actions workflows:
+
+```cmake
+-DVCPKG_OVERLAY_PORTS=${github.workspace}/cmake/overlays
+```
+
+For local development on Windows:
+```bash
+cmake -B build -DVCPKG_OVERLAY_PORTS=cmake/overlays ...
+```
+
+## Maintenance
+
+- Overlays are version-specific (currently SDL2 2.30.9)
+- When updating SDL2 version in vcpkg.json, check if the overlay needs updating
+- Monitor upstream vcpkg for fixes that would allow removing these overlays
+