ci: Add PyPI trusted publisher workflow

Enables secure tokenless publishing via OIDC:
- Triggers on GitHub release published
- Builds wheel and sdist
- Publishes using trusted publisher (no API token)

Requires configuring trusted publisher on PyPI:
- Owner: Smart-AI-Memory
- Repo: empathy-framework
- Workflow: publish-pypi.yml

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <[email protected]>

Author: 2 people

.github/workflows/publish-pypi.yml

@@ -0,0 +1,45 @@
+name: Publish to PyPI
+
+on:
+  release:
+    types: [published]
+
+jobs:
+  build:
+    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 dependencies
+        run: pip install build
+
+      - name: Build package
+        run: python -m build
+
+      - name: Upload artifacts
+        uses: actions/upload-artifact@v4
+        with:
+          name: dist
+          path: dist/
+
+  publish:
+    needs: build
+    runs-on: ubuntu-latest
+    environment: pypi
+    permissions:
+      id-token: write  # Required for trusted publishing
+    steps:
+      - name: Download artifacts
+        uses: actions/download-artifact@v4
+        with:
+          name: dist
+          path: dist/
+
+      - name: Publish to PyPI
+        uses: pypa/gh-action-pypi-publish@release/v1
+        # No token needed - uses OIDC trusted publishing