CI helpers for setup-host releases

Shared scripts and GitHub Actions so new PSXRecomp titles do not reimplement toolchain fetch, emitter staging, or Windows MinGW DLL bundling.

Start here for a new game repo: ../GAME_PROJECT_SETUP.md

Workflow template

Copy into the game repository (not into this framework alone):

mkdir -p .github/workflows
cp psxrecomp/docs/ci/templates/setup-release.yml .github/workflows/release.yml
# edit YOUR_* placeholders

Template path: templates/setup-release.yml

A shorter stub also lives at setup-release.yml.example (points at the full template).

Tools

Script	Role
`tools/fetch_toolchain.sh`	Download/unpack `cmake-clang-v1` from retcomm-toolchains
`tools/stage_setup_sdk.sh`	Stage emitters, OpenBIOS checks, `toolchain/`, MinGW DLLs
`tools/bundle_mingw_dlls.sh`	Copy imported non-system DLLs next to Windows PEs

Composite actions

Use from a game repo after actions/checkout with submodules: recursive:

- uses: ./psxrecomp/.github/actions/fetch-toolchain
  with:
    artifact: ${{ matrix.artifact }}   # linux-x64 | windows-x64 | macos-arm64 | macos-x64

- uses: ./psxrecomp/.github/actions/stage-setup-sdk
  with:
    stage: dist/stage-setup-${{ matrix.artifact }}
    sdk-overlay: psxrecomp-sdk
    recompiler-build: build-recompiler
    runtime-bin: /mingw64/bin          # Windows / MSYS2 only

fetch-toolchain exports TOOLCHAIN_DIR, PSXRECOMP_TOOLCHAIN_DIR, and BPE_TOOLCHAIN_DIR via GITHUB_ENV for later steps.

Title responsibilities

Keep in the game repo:

Setup-host CMake flags and exe basename
Copying game sources / assets into the stage
Zip naming and release notes
Thin scripts/package_setup_release.sh that stages title files then calls psxrecomp/tools/stage_setup_sdk.sh

Release checklist

See the Bundled release checklist in ../GAME_PROJECT_SETUP.md.