ci: add PyPI publish workflow (PILOT-203)

.github/workflows/publish.yml

@@ -0,0 +1,56 @@
+name: publish
+
+# PILOT-203: PyPI publish workflow.
+#
+# Triggers on:
+#   - Release published (the normal path: tag a release on GitHub → publish)
+#   - workflow_dispatch (manual fallback when a release was created but
+#     publish missed it, or when republishing on a fresh PYPI_API_TOKEN)
+#
+# Required secret:
+#   PYPI_API_TOKEN — pypi.org token scoped to the pilotprotocol project.
+
+on:
+  release:
+    types: [published]
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+    name: Build wheel + sdist
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.12'
+      - run: python -m pip install --upgrade build twine
+      - run: python -m build
+      - run: python -m twine check dist/*
+      - uses: actions/upload-artifact@v4
+        with:
+          name: dist
+          path: dist/
+          retention-days: 7
+
+  publish:
+    name: Publish to PyPI
+    needs: build
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      # OIDC for trusted publisher (preferred). Falls back to API token
+      # when configured below.
+      id-token: write
+    steps:
+      - uses: actions/download-artifact@v4
+        with:
+          name: dist
+          path: dist/
+      - uses: pypa/gh-action-pypi-publish@release/v1
+        with:
+          password: ${{ secrets.PYPI_API_TOKEN }}
+          verbose: true