Add CI/CD workflow for building wheels and publishing to PyPI

Uses cibuildwheel to build platform wheels on Linux, macOS, and Windows.
Publishes to PyPI via trusted publishing on v* tag pushes.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Transurgeon

.github/workflows/build-and-publish.yml

@@ -0,0 +1,63 @@
+name: Build and publish
+
+on:
+  push:
+    tags:
+      - 'v*'
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  build_wheels:
+    name: Build wheels on ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, windows-latest, macos-13, macos-14]
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          submodules: true
+
+      - name: Build wheels
+        uses: pypa/cibuildwheel@v2.22.0
+        env:
+          CIBW_ARCHS_MACOS: "x86_64 arm64"
+
+      - uses: actions/upload-artifact@v4
+        with:
+          name: cibw-wheels-${{ matrix.os }}-${{ strategy.job-index }}
+          path: ./wheelhouse/*.whl
+
+  build_sdist:
+    name: Build source distribution
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          submodules: true
+
+      - name: Build sdist
+        run: pipx run build --sdist
+
+      - uses: actions/upload-artifact@v4
+        with:
+          name: cibw-sdist
+          path: ./dist/*.tar.gz
+
+  upload_pypi:
+    needs: [build_wheels, build_sdist]
+    runs-on: ubuntu-latest
+    environment: pypi
+    permissions:
+      id-token: write
+    if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/v')
+    steps:
+      - uses: actions/download-artifact@v4
+        with:
+          pattern: cibw-*
+          path: dist
+          merge-multiple: true
+
+      - name: Publish to PyPI
+        uses: pypa/gh-action-pypi-publish@release/v1