docs: move public docs generation to local workflow

.github/workflows/generate-docs.yml

@@ -1,4 +1,4 @@
-name: Generate documentation
+name: Validate committed public docs
 
 on:
   push:
@@ -16,53 +16,16 @@ on:
       - "docs/public/**"
       - "site/**"
   workflow_dispatch:
-    inputs:
-      commit_generated_docs:
-        description: "Commit generated docs back to the branch"
-        required: false
-        default: "false"
-        type: choice
-        options: ["false", "true"]
 
 permissions:
-  contents: write
+  contents: read
 
 jobs:
-  generate-docs:
+  validate-public-docs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-        with:
-          fetch-depth: 0
-      - name: Install tooling
+      - name: Ensure committed docs/public exists
         run: |
-          sudo apt-get update
-          sudo apt-get install -y graphviz jq python3 python3-pip
-          if ! docker compose version >/dev/null 2>&1; then
-            sudo apt-get install -y docker-compose-v2 || sudo apt-get install -y docker-compose || true
-          fi
-          if ! docker compose version >/dev/null 2>&1; then
-            echo "docker compose CLI is unavailable on this runner" >&2
-            exit 1
-          fi
-          python3 -m pip install --user pyyaml jinja2
-      - name: Generate documentation
-        run: |
-          chmod +x scripts/docs/*.sh
-          scripts/docs/generate-all.sh
-      - name: Upload generated documentation
-        uses: actions/upload-artifact@v4
-        with:
-          name: generated-documentation
-          path: |
-            docs/generated
-            docs/diagrams
-            docs/public
-      - name: Commit generated docs
-        if: >
-          github.event_name == 'push' ||
-          (github.event_name == 'workflow_dispatch' && inputs.commit_generated_docs == 'true')
-        uses: stefanzweifel/git-auto-commit-action@v5
-        with:
-          commit_message: "docs: regenerate environment documentation"
-          file_pattern: docs/generated docs/diagrams docs/public
+          test -d docs/public
+          test -n "$(find docs/public -mindepth 1 -print -quit)"