Revert "Delete quality.yml"

This reverts commit 4d5e052.

Author: rafatosta

.github/workflows/quality.yml

@@ -0,0 +1,32 @@
+name: Quality
+
+on:
+  workflow_dispatch:
+  pull_request:
+  push:
+    branches:
+      - main
+
+permissions:
+  contents: read
+
+jobs:
+  structural-contract:
+    name: Structural documentation
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+
+      - name: Validate package manifest
+        run: python tests/check_unused_code.py --packages-only
+
+      - name: Validate documented structure
+        run: python tests/test_documentation_structure.py -v
+
+      - name: Compile Python sources
+        run: python -m compileall -q zapzap tests tools run.py