Add PyPI auto-publish workflow on version tag push

When a tag matching 'v*' is pushed, the workflow builds and publishes
to PyPI automatically.

Co-Authored-By: deepseek-v4-pro

Author: zhengjiang shao

.github/workflows/publish.yml

@@ -0,0 +1,25 @@
+name: Publish to PyPI
+
+on:
+  push:
+    tags:
+      - 'v*'
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+      - name: Install build tools
+        run: pip install build twine
+      - name: Build package
+        run: python -m build
+      - name: Publish to PyPI
+        run: twine upload dist/*
+        env:
+          TWINE_USERNAME: __token__
+          TWINE_PASSWORD: ${{ secrets.PYPI_TOKEN }}