Add tag-based release workflow

Author: CongkeChen

.github/workflows/release.yml

@@ -0,0 +1,70 @@
+name: Auto Release when Tag
+on:
+  push:
+    tags:
+      - 'v*'
+      - 'test/v*'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: false
+
+permissions:
+  contents: read
+
+jobs:
+  release:
+    runs-on: [self-hosted, trpc-agent-python-ci]
+    timeout-minutes: 30
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install release dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install -r requirements-test.txt
+          pip install build twine flake8 yapf
+
+      - name: Validate tag version
+        run: |
+          TAG_VERSION="${GITHUB_REF_NAME#test/v}"
+          TAG_VERSION="${TAG_VERSION#v}"
+          PACKAGE_VERSION=$(python -c "from trpc_agent_sdk.version import __version__; print(__version__)")
+          if [ "$TAG_VERSION" != "$PACKAGE_VERSION" ]; then
+            echo "::error::Tag version '$TAG_VERSION' does not match package version '$PACKAGE_VERSION'."
+            exit 1
+          fi
+
+      - name: Check formatting with YAPF
+        run: |
+          diff_output=$(yapf --diff --recursive trpc_agent_sdk) || true
+          if [ -n "$diff_output" ]; then
+            echo "$diff_output"
+            echo "::error::Code formatting check failed. Run 'yapf -i -r trpc_agent_sdk' to fix."
+            exit 1
+          fi
+
+      - name: Lint with flake8
+        run: |
+          flake8 trpc_agent_sdk
+
+      - name: Run tests with coverage
+        run: |
+          pytest --cov=trpc_agent_sdk --cov-report=xml --cov-report=term --cov-fail-under=80 tests/
+
+      - name: Build package
+        run: |
+          python -m build
+
+      - name: Check package
+        run: |
+          twine check dist/*
+
+      - name: Publish to PyPI
+        if: startsWith(github.ref, 'refs/tags/v')
+        run: |
+          twine upload dist/*
+        env:
+          TWINE_USERNAME: __token__
+          TWINE_PASSWORD: ${{ secrets.PYPI_TOKEN }}