Add GitHub Actions workflow for rendering demo images automatically on main branch updates

Author: FridrichMethod

.github/workflows/render-demos.yml

@@ -0,0 +1,56 @@
+name: Render demos
+
+on:
+  push:
+    branches: [main]
+    paths:
+      - "configs/.pymolrc"
+      - "configs/.pymolrc.py"
+  workflow_dispatch:
+
+jobs:
+  render:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Setup Miniconda
+        uses: conda-incubator/setup-miniconda@v3
+        with:
+          miniforge-variant: Mambaforge
+          channels: conda-forge,defaults
+          channel-priority: strict
+
+      - name: Install PyMOL and Xvfb
+        shell: bash -l {0}
+        run: |
+          mamba install -y pymol-open-source xvfb-run
+
+      - name: Render demos
+        shell: bash -l {0}
+        env:
+          PYMOLRC: ${{ github.workspace }}/configs/.pymolrc
+        run: |
+          mkdir -p assets
+          for pml in scripts/demos/*.pml; do
+            name=$(basename "$pml" .pml)
+            echo "Rendering $name..."
+            xvfb-run -a pymol -cqxi "$pml"
+          done
+          ls -la assets/
+
+      - name: Commit rendered PNGs
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "github-actions[bot]@users.noreply.github.com"
+          git add assets/*.png
+          if git diff --staged --quiet; then
+            echo "No PNG changes"
+          else
+            git commit -m "chore: re-render demos after config update"
+            git push origin HEAD:${{ github.ref }}
+          fi