Split macos-13 into a separate Build Legacy Wheels workflow

.github/workflows/build-legacy-wheels.yml

@@ -0,0 +1,83 @@
+name: Build Legacy Wheels (macos-13)
+
+on:
+  pull_request:
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  build_legacy_wheels:
+    name: macos-13
+    runs-on: macos-13
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+
+      - name: Download model weights from release v0.1.1
+        shell: bash
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          set -euxo pipefail
+          mkdir -p src/pyfacewipe/models
+          gh release download v0.1.1 \
+            -R "${GITHUB_REPOSITORY}" \
+            -p "synthstrip.1.pt" \
+            -p "synthstrip.nocsf.1.pt" \
+            -D src/pyfacewipe/models
+          ls -lah src/pyfacewipe/models
+
+      - name: Build wheels
+        uses: pypa/cibuildwheel@v2.22.0
+        env:
+          CIBW_BUILD: "cp38-* cp39-* cp310-* cp311-* cp312-*"
+          CIBW_SKIP: "pp* *-musllinux_* *-win32"
+          CIBW_ARCHS_MACOS: "x86_64 arm64"
+          CIBW_BUILD_VERBOSITY: "1"
+
+      - name: Verify wheels contain model weights
+        shell: bash
+        run: |
+          set -euxo pipefail
+          python - <<'PY'
+          import glob
+          import sys
+          import zipfile
+
+          whls = glob.glob("wheelhouse/*.whl")
+          if not whls:
+              print("No wheels found in wheelhouse/*.whl", file=sys.stderr)
+              sys.exit(1)
+
+          required = {
+              "pyfacewipe/models/synthstrip.1.pt",
+              "pyfacewipe/models/synthstrip.nocsf.1.pt",
+          }
+
+          missing_any = False
+          for whl in whls:
+              with zipfile.ZipFile(whl) as z:
+                  names = set(z.namelist())
+              missing = sorted(required - names)
+              if missing:
+                  missing_any = True
+                  print(f"ERROR: {whl} is missing: {missing}", file=sys.stderr)
+              else:
+                  print(f"OK: {whl} contains model weights")
+
+          sys.exit(1 if missing_any else 0)
+          PY
+
+      - name: Upload wheels
+        uses: actions/upload-artifact@v4
+        with:
+          name: wheels-${{ runner.os }}-legacy-macos-13
+          path: wheelhouse/*.whl

.github/workflows/build-wheels.yml

@@ -11,7 +11,9 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest, windows-latest, macos-13, macos-14]
+        # macos-13 is handled in build-legacy-wheels.yml because its
+        # GitHub-hosted runners are intermittently unavailable.
+        os: [ubuntu-latest, windows-latest, macos-14]
 
     steps:
       - name: Checkout