Add self-contained GitHub Actions lab

Author: adhamcodes

examples/actions/README.md

@@ -0,0 +1,43 @@
+# Controlled GitHub Actions Lab
+
+This lab removes the need to hunt for a random public workflow. Run it in your disposable `git-github-lab` repository.
+
+## 1. Copy the demo
+
+Copy these files into your student lab:
+
+- `examples/actions/demo/app.py` → `app.py`
+- `examples/actions/demo/tests/test_app.py` → `tests/test_app.py`
+- `examples/actions/basic-python-ci.yml` → `.github/workflows/ci.yml`
+
+Commit and push them.
+
+## 2. Inspect before running
+
+Open `.github/workflows/ci.yml` and identify:
+
+- the events under `on`
+- the job under `jobs`
+- the runner
+- each step
+- the command that decides whether the check passes
+
+## 3. Prove green
+
+Open the Actions tab or the commit checks. Confirm the tests pass.
+
+## 4. Break it deliberately
+
+Change `add(2, 3)` in the test expectation so the test is wrong, commit, and push.
+
+Predict the result before checking GitHub.
+
+Confirm the workflow fails and inspect the failing test output.
+
+## 5. Repair
+
+Fix the test, commit, push, and verify the workflow returns to green.
+
+## Pass condition
+
+You can explain why CI is useful, what caused the red check, and why a green check only proves the checks that actually ran—not all possible correctness.