Add Windows cross-build and Gitea release; share CI setup

- just windows-deps / windows / package-windows: cross-compile with Odin
  objects + lld-link against an xwin SDK, static VC runtime
- Release workflow runs on v* tags, builds Linux and Windows packages,
  uploads them to the package registry and creates a Gitea release
- Shared toolchain setup as a local composite action

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.gitea/actions/setup/action.yaml

@@ -0,0 +1,44 @@
+#
+# .gitea/actions/setup/action.yaml
+#
+# Installs the toolchain shared by all workflows: system packages, Odin and just.
+#
+
+name: "Setup Odin toolchain"
+description: "Install system packages, Odin and just"
+
+inputs:
+  odin-version:
+    description: "Odin release tag (keep in sync with odin_version in the justfile)"
+    default: "dev-2026-09"
+  packages:
+    description: "Extra apt packages to install"
+    default: ""
+
+runs:
+  using: "composite"
+  steps:
+    - name: Install System Packages
+      shell: bash
+      run: |
+        SUDO=""; command -v sudo >/dev/null && SUDO=sudo
+        $SUDO apt-get update
+        # clang links Odin programs on Linux; raylib needs X11
+        $SUDO apt-get install -y --no-install-recommends \
+          clang libx11-dev curl ca-certificates unzip ${{ inputs.packages }}
+
+    - name: Install Odin
+      shell: bash
+      run: |
+        curl -fsSL -o /tmp/odin.tar.gz \
+          https://github.com/odin-lang/Odin/releases/download/${{ inputs.odin-version }}/odin-linux-amd64-${{ inputs.odin-version }}.tar.gz
+        mkdir -p "$HOME/odin"
+        tar -xzf /tmp/odin.tar.gz -C "$HOME/odin" --strip-components=1
+        echo "$HOME/odin" >> "$GITHUB_PATH"
+
+    - name: Install just
+      shell: bash
+      run: |
+        mkdir -p "$HOME/.local/bin"
+        curl --proto '=https' --tlsv1.2 -sSf https://just.systems/install.sh | bash -s -- --to "$HOME/.local/bin"
+        echo "$HOME/.local/bin" >> "$GITHUB_PATH"

.gitea/workflows/gitea-build.yaml

@@ -1,7 +1,7 @@
 #
 # .gitea/workflows/gitea-build.yaml
 #
-# Builds and tests on every push and pull request to main and develop.
+# Checks, tests and builds on every push and pull request to main and develop.
 #
 
 name: "Build and Test"
@@ -11,9 +11,6 @@ on:
   pull_request:
     branches: [main, develop]
 
-env:
-  ODIN_VERSION: dev-2026-09
-
 jobs:
   build:
     runs-on: ubuntu-latest
@@ -21,25 +18,8 @@ jobs:
       - name: Checkout Repository
         uses: actions/checkout@v4
 
-      - name: Install System Dependencies
-        run: |
-          SUDO=""; command -v sudo >/dev/null && SUDO=sudo
-          $SUDO apt-get update
-          # clang links Odin programs; raylib needs X11 on Linux
-          $SUDO apt-get install -y --no-install-recommends clang libx11-dev curl ca-certificates
-
-      - name: Install Odin
-        run: |
-          curl -fsSL -o odin.tar.gz https://github.com/odin-lang/Odin/releases/download/$ODIN_VERSION/odin-linux-amd64-$ODIN_VERSION.tar.gz
-          mkdir -p "$HOME/odin"
-          tar -xzf odin.tar.gz -C "$HOME/odin" --strip-components=1
-          echo "$HOME/odin" >> "$GITHUB_PATH"
-
-      - name: Install just
-        run: |
-          mkdir -p "$HOME/.local/bin"
-          curl --proto '=https' --tlsv1.2 -sSf https://just.systems/install.sh | bash -s -- --to "$HOME/.local/bin"
-          echo "$HOME/.local/bin" >> "$GITHUB_PATH"
+      - name: Setup Toolchain
+        uses: ./.gitea/actions/setup
 
       - name: Check
         run: |

.gitea/workflows/gitea-release.yaml

@@ -1,47 +1,33 @@
 #
 # .gitea/workflows/gitea-release.yaml
 #
-# Builds a release package on version branches (e.g. 1.0) and uploads it to
-# the Gitea generic package registry.
+# On a version tag (e.g. v1.0): tests, builds Linux and Windows packages,
+# uploads them to the Gitea generic package registry and creates a Gitea release.
 #
 
-name: "Publish"
+name: "Release"
 on:
   push:
-    branches:
-      - '*.*'
+    tags:
+      - 'v*'
 
 env:
-  ODIN_VERSION: dev-2026-09
   PROJECT_NAME: HanjaKanaMun
-  GAME_VERSION: ${{gitea.ref_name}}
 
 jobs:
-  build:
+  release:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout Repository
         uses: actions/checkout@v4
 
-      - name: Install System Dependencies
-        run: |
-          SUDO=""; command -v sudo >/dev/null && SUDO=sudo
-          $SUDO apt-get update
-          # clang links Odin programs; raylib needs X11 on Linux
-          $SUDO apt-get install -y --no-install-recommends clang libx11-dev curl ca-certificates
+      - name: Setup Toolchain
+        uses: ./.gitea/actions/setup
+        with:
+          packages: lld zip
 
-      - name: Install Odin
-        run: |
-          curl -fsSL -o odin.tar.gz https://github.com/odin-lang/Odin/releases/download/$ODIN_VERSION/odin-linux-amd64-$ODIN_VERSION.tar.gz
-          mkdir -p "$HOME/odin"
-          tar -xzf odin.tar.gz -C "$HOME/odin" --strip-components=1
-          echo "$HOME/odin" >> "$GITHUB_PATH"
-
-      - name: Install just
-        run: |
-          mkdir -p "$HOME/.local/bin"
-          curl --proto '=https' --tlsv1.2 -sSf https://just.systems/install.sh | bash -s -- --to "$HOME/.local/bin"
-          echo "$HOME/.local/bin" >> "$GITHUB_PATH"
+      - name: Set Version
+        run: echo "GAME_VERSION=${GITHUB_REF_NAME#v}" >> "$GITHUB_ENV"
 
       - name: Test
         run: just test
@@ -49,10 +35,30 @@ jobs:
       - name: Linux Build
         run: just package "$GAME_VERSION"
 
-      - name: Upload Artifact Linux
+      - name: Windows Build
+        run: |
+          # Debian/Ubuntu may only ship a versioned lld-link
+          LLD_LINK="$(command -v lld-link || ls /usr/lib/llvm-*/bin/lld-link | sort -V | tail -1)"
+          export LLD_LINK
+          just windows-deps
+          just package-windows "$GAME_VERSION"
+
+      - name: Upload Artifacts
         run: |
           ls -la build
-          FILE="${PROJECT_NAME}_${GAME_VERSION}_linux_x86_64.tar.gz"
+          for FILE in build/${PROJECT_NAME}_${GAME_VERSION}_*; do
+            NAME="$(basename "$FILE")"
+            echo "Uploading $NAME"
             curl --fail --user ${{ github.repository_owner }}:${{ secrets.TOKEN }} \
-                --upload-file "build/$FILE" \
-                https://gitea.sanplex.xyz/api/packages/sansan/generic/$PROJECT_NAME/$GAME_VERSION/$FILE
+                  --upload-file "$FILE" \
+                  https://gitea.sanplex.xyz/api/packages/sansan/generic/$PROJECT_NAME/$GAME_VERSION/$NAME
+          done
+
+      - name: Create Release
+        uses: akkuman/gitea-release-action@v1
+        env:
+          NODE_OPTIONS: '--experimental-fetch' # if nodejs < 18
+        with:
+          files: |-
+            build/${{ env.PROJECT_NAME }}_*.tar.gz
+            build/${{ env.PROJECT_NAME }}_*.zip

AGENTS.md

@@ -33,6 +33,7 @@ Commands (see `justfile`): `just run`, `just check`, `just test`, `just package
 2. **Old font failure root cause**: `DroidSansJapanese.ttf` was a GitHub HTML page saved from a blob URL, not a font. Always download fonts from raw URLs and check them with `file`.
 3. **Thai shaping**: raylib does no text shaping, so Thai combining vowels/tone marks may be misplaced. Prefer standalone consonants on Thai cards.
 4. Tests share the memory game's global state, so they must run single-threaded (`just test` sets `ODIN_TEST_THREADS=1`).
+6. **Windows builds are cross-compiled**: Odin can't link Windows binaries on Linux, so `just windows` builds objects with `-build-mode:obj` and links with `lld-link` against an xwin SDK. The VC runtime is linked statically; only Windows system DLLs are needed. Not yet tested on a real Windows machine.
 5. The game changes directory to the executable's folder at startup so `assets/` is found from anywhere.
 
 ## File Structure
@@ -43,9 +44,11 @@ HanjaKanaMun/
 ├── justfile               # build/run/check/test/package recipes
 ├── ols.json               # ols language server settings (neovim)
 ├── odinfmt.json           # odinfmt formatter settings (4 spaces, LF)
-├── .gitea/workflows/
+├── .gitea/
+│   ├── actions/setup/      # shared CI toolchain setup (apt, Odin, just)
+│   └── workflows/
 │       ├── gitea-build.yaml    # check + test + build on main/develop
-│   └── gitea-release.yaml  # package on version branches (*.*), upload to Gitea packages
+│       └── gitea-release.yaml  # on tags v*: Linux + Windows packages, package registry upload, Gitea release
 ├── main.odin              # Window/audio setup, screen state machine
 ├── src/
 │   ├── themes/themes.odin  # Theme struct, flag colors, Screen/Flag enums, layout constants

README.md

@@ -10,9 +10,15 @@ Requires [Odin](https://odin-lang.org) (dev-2026-09) and [just](https://just.sys
 just run              # build and play (debug)
 just check            # type-check with -vet
 just test             # run tests
-just package 1.0      # release build -> build/HanjaKanaMun_1.0_<os>_<arch>.tar.gz
+just package 1.0      # native release build -> build/HanjaKanaMun_1.0_<os>_<arch>.tar.gz
+just windows-deps     # Linux only: fetch Windows SDK/CRT (xwin) and raylib.lib
+just package-windows 1.0  # cross-compiled Windows build -> build/HanjaKanaMun_1.0_windows_x86_64.zip
 ```
 
+The Windows build needs `lld-link`. On macOS, `brew install lld` and set `LLD_LINK`, and point `XWIN_SDK` and
+`RAYLIB_WINDOWS` at an xwin splat and Odin's Windows `vendor/raylib/windows` folder (the Linux/macOS Odin releases
+don't include `raylib.lib`).
+
 ### Neovim
 
 `ols.json` and `odinfmt.json` configure the [ols](https://github.com/DanielGavin/ols) language server and formatter.
@@ -22,8 +28,12 @@ Formatting goes through ols (`vim.lsp.buf.format()`), or `just fmt` if `odinfmt`
 ## CI
 
 - `.gitea/workflows/gitea-build.yaml`: check, test and build on pushes and PRs to `main` and `develop`.
-- `.gitea/workflows/gitea-release.yaml`: on version branches like `1.0`, packages the Linux build and uploads it to
-  the Gitea generic package registry (`HanjaKanaMun/<version>`). Needs a `TOKEN` secret with package write access.
+- `.gitea/workflows/gitea-release.yaml`: on a version tag like `v1.0`, builds Linux and Windows packages, uploads them
+  to the Gitea generic package registry (`HanjaKanaMun/1.0`) and creates a Gitea release with both attached.
+  Needs a `TOKEN` secret with package write access.
+- `.gitea/actions/setup`: shared toolchain setup (apt packages, Odin, just).
+
+Release: `git tag v1.0 && git push origin v1.0`
 
 ## Credits
 

justfile

@@ -1,5 +1,13 @@
 name := "HanjaKanaMun"
 build_dir := "build"
+odin_version := "dev-2026-09"
+xwin_version := "0.10.0"
+
+# Windows cross-compilation inputs (see `windows-deps`)
+xwin := env("XWIN", build_dir / "xwin")
+xwin_sdk := env("XWIN_SDK", build_dir / "xwin-sdk")
+raylib_windows := env("RAYLIB_WINDOWS", build_dir / "raylib-windows")
+lld_link := env("LLD_LINK", "lld-link")
 
 # List available recipes
 default:
@@ -22,17 +30,65 @@ test:
     mkdir -p {{build_dir}}
     odin test tests -vet -define:ODIN_TEST_THREADS=1 -out:{{build_dir}}/tests
 
-# Optimized build into build/, with the assets it needs at runtime
+# Optimized native build into build/<os>/, with the assets it needs at runtime
 release:
-    mkdir -p {{build_dir}}/{{name}}
-    odin build . -vet -o:speed -out:{{build_dir}}/{{name}}/{{name}}
-    cp -R assets {{build_dir}}/{{name}}/
+    mkdir -p {{build_dir}}/{{os()}}/{{name}}
+    odin build . -vet -o:speed -out:{{build_dir}}/{{os()}}/{{name}}/{{name}}
+    cp -R assets {{build_dir}}/{{os()}}/{{name}}/
 
-# Release build packed as build/<name>_<version>_<os>_<arch>.tar.gz
+# Native release build packed as build/<name>_<version>_<os>_<arch>.tar.gz
 package version="dev": release
-    tar -czf {{build_dir}}/{{name}}_{{version}}_{{os()}}_{{arch()}}.tar.gz -C {{build_dir}} {{name}}
+    tar -czf {{build_dir}}/{{name}}_{{version}}_{{os()}}_{{arch()}}.tar.gz -C {{build_dir}}/{{os()}} {{name}}
     @echo "{{build_dir}}/{{name}}_{{version}}_{{os()}}_{{arch()}}.tar.gz"
 
+# Download the Windows SDK + CRT (via xwin, accepting Microsoft's license) and raylib.lib. Linux x86_64 only.
+windows-deps:
+    #!/usr/bin/env bash
+    set -euo pipefail
+    mkdir -p {{build_dir}}
+    if [ ! -x "{{xwin}}" ]; then
+        curl -fsSL https://github.com/Jake-Shadle/xwin/releases/download/{{xwin_version}}/xwin-{{xwin_version}}-x86_64-unknown-linux-musl.tar.gz \
+            | tar -xz -C {{build_dir}} --strip-components=1 xwin-{{xwin_version}}-x86_64-unknown-linux-musl/xwin
+    fi
+    if [ ! -d "{{xwin_sdk}}/crt" ]; then
+        "{{xwin}}" --accept-license --arch x86_64 --cache-dir {{build_dir}}/xwin-cache splat --output "{{xwin_sdk}}"
+    fi
+    # Odin's Linux/macOS releases don't ship raylib's Windows library, so take it from the Windows release
+    if [ ! -f "{{raylib_windows}}/raylib.lib" ]; then
+        mkdir -p "{{raylib_windows}}"
+        curl -fsSL -o {{build_dir}}/odin-windows.zip \
+            https://github.com/odin-lang/Odin/releases/download/{{odin_version}}/odin-windows-amd64-{{odin_version}}.zip
+        unzip -o -j {{build_dir}}/odin-windows.zip 'dist/vendor/raylib/windows/raylib.lib' -d "{{raylib_windows}}"
+    fi
+
+# Cross-compile a Windows x86_64 build into build/windows/ (run `just windows-deps` first)
+windows:
+    #!/usr/bin/env bash
+    set -euo pipefail
+    obj_dir={{build_dir}}/obj-windows
+    out_dir={{build_dir}}/windows/{{name}}
+    mkdir -p "$obj_dir" "$out_dir"
+    rm -f "$obj_dir"/*.obj
+    odin build . -vet -o:speed -target:windows_amd64 -build-mode:obj -out:"$obj_dir/{{name}}.obj"
+    # Odin can't link for Windows from other platforms, so link with lld-link.
+    # The VC runtime is linked statically (no VCRUNTIME140.dll needed); the
+    # Universal CRT is used from Windows itself (built into Windows 10+).
+    {{lld_link}} /nologo /machine:x64 /subsystem:windows /entry:mainCRTStartup \
+        /out:"$out_dir/{{name}}.exe" "$obj_dir"/*.obj "{{raylib_windows}}/raylib.lib" \
+        /libpath:"{{xwin_sdk}}/crt/lib/x86_64" \
+        /libpath:"{{xwin_sdk}}/sdk/lib/um/x86_64" \
+        /libpath:"{{xwin_sdk}}/sdk/lib/ucrt/x86_64" \
+        /nodefaultlib:msvcrt /nodefaultlib:vcruntime /nodefaultlib:libucrt \
+        libcmt.lib libvcruntime.lib ucrt.lib \
+        kernel32.lib user32.lib gdi32.lib winmm.lib shell32.lib opengl32.lib \
+        advapi32.lib bcrypt.lib ntdll.lib synchronization.lib
+    cp -R assets "$out_dir/"
+
+# Windows build packed as build/<name>_<version>_windows_x86_64.zip
+package-windows version="dev": windows
+    cd {{build_dir}}/windows && zip -qr ../{{name}}_{{version}}_windows_x86_64.zip {{name}}
+    @echo "{{build_dir}}/{{name}}_{{version}}_windows_x86_64.zip"
+
 # Format all Odin files with odinfmt (settings in odinfmt.json)
 fmt:
     odinfmt -w .