Add tag-triggered PyPI publish workflow via Trusted Publishing

.github/workflows/publish.yml

@@ -0,0 +1,38 @@
+name: Publish to PyPI
+
+on:
+  push:
+    tags: ["v*"]
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    environment: pypi
+    permissions:
+      id-token: write # required for PyPI Trusted Publishing (OIDC), no token secret needed
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install uv
+        uses: astral-sh/setup-uv@v3
+        with:
+          version: "latest"
+
+      - name: Set up Python
+        run: uv python install 3.12
+
+      - name: Verify tag matches pyproject.toml version
+        run: |
+          TAG_VERSION="${GITHUB_REF_NAME#v}"
+          PYPROJECT_VERSION=$(grep -m1 '^version = ' pyproject.toml | sed -E 's/version = "(.*)"/\1/')
+          if [ "$TAG_VERSION" != "$PYPROJECT_VERSION" ]; then
+            echo "Tag v$TAG_VERSION does not match pyproject.toml version $PYPROJECT_VERSION"
+            exit 1
+          fi
+
+      - name: Build
+        run: uv build
+
+      - name: Publish to PyPI
+        run: uv publish