Add Step 12 compile-first iteration guidance to reduce workflow-not-compiled dropoff (#1651)

Author: Copilot

workshop/00-welcome.md

@@ -10,6 +10,8 @@ By the end of this workshop, a real AI agent will create an issue with a summary
 
 You'll build an **[Agentic Workflow](https://github.github.com/gh-aw/introduction/overview/)**: a GitHub Action that uses AI to inspect your repository, decide what matters, and publish a useful status report on a schedule — practical enough to adapt for real teams.
 
+Along the way, you'll compile the workflow, trigger test runs, and iterate on the prompt until the output matches your intent.
+
 ![Preview of a completed workflow run in the Actions tab](images/00-workflow-run-complete.svg)
 
 <!-- journey: all -->

workshop/09-agentic-editing.md

@@ -131,5 +131,5 @@ Review the Markdown body of your workflow and remove any sentences that repeat t
 - [ ] I re-ran the workflow from **Actions** and confirmed the updated output matches my intent
 
 <!-- journey: all -->
-**Next:** [What's Next? Keep Exploring](14-next-steps.md)
+**Next:** [Test and Improve Your Workflow](12-test-and-iterate.md)
 <!-- /journey -->

workshop/12-test-and-iterate.md

@@ -0,0 +1,99 @@
+<!-- page-journey: all -->
+<!-- page-adventure: core -->
+# Test and Improve Your Workflow
+
+_The fastest path to a better workflow is a tight loop: change one thing, compile, test, and compare the result._
+
+## 🎯 What You'll Do
+
+You'll make one small improvement to your workflow, recompile it before testing, trigger a fresh run, and compare the new output against the previous one.
+
+By the end of this step, you'll have a repeatable iteration loop you can use any time the workflow output is vague, incorrect, or missing something important.
+
+## 📋 Before You Start
+
+- You have a working workflow draft from [Refine Your Workflow with Agentic Editing](09-agentic-editing.md) or an equivalent earlier build step in your chosen path.
+- You have at least one completed workflow run to inspect.
+- You can edit the workflow in a terminal, Codespace, or Copilot agent session.
+
+## Start With One Concrete Observation
+
+Open the latest run in the **Actions** tab and look for one thing you want to improve.
+
+Good examples:
+
+- The summary is too generic.
+- An important detail is missing.
+- The tone feels too stiff.
+- The formatting is inconsistent.
+
+Pick only one problem for this round. Small, isolated changes make it much easier to tell what actually improved the result.
+
+## Make One Targeted Change
+
+Open your workflow source file, such as `.github/workflows/daily-status.md`, and change only one instruction in the Markdown body or the YAML frontmatter at the top of the file.
+
+Examples of focused changes:
+
+- ask for a shorter or more structured output format
+- name one missing field the agent should include
+- add a fallback instruction for empty results
+- tighten one permission or safe-output rule
+
+If you are using a Copilot agent to edit the file, tell it to make the change, review the diff, and then run `gh aw compile` before testing.
+
+> [!IMPORTANT]
+> Compile after every workflow edit before you test it. GitHub Actions runs the compiled `.lock.yml` file, not the source `.md` file, so skipping `gh aw compile` means you are testing stale workflow logic.
+
+## Compile Before You Test
+
+From your repository root, run:
+
+```bash
+gh aw compile
+```
+
+This updates the compiled lock file that GitHub Actions actually executes.
+
+If the compiler reports an error, fix that first. Do not start a new test run until compilation succeeds.
+
+> [!TIP]
+> If you expect to make several small edits in a row, `gh aw compile --watch` can speed up the loop by recompiling after each save.
+
+## Commit Both Workflow Files
+
+After `gh aw compile` succeeds, commit both the source workflow and the regenerated lock file:
+
+```bash
+git add .github/workflows/daily-status.md .github/workflows/daily-status.lock.yml
+git commit -m "refine daily-status workflow output"
+git push
+```
+
+If your workflow uses a different filename, stage that `.md` file and its matching `.lock.yml` file instead.
+
+## Trigger a Fresh Run and Compare
+
+Use **workflow_dispatch** from the **Actions** tab to trigger a new run. Then compare the latest result with the previous one.
+
+Ask yourself:
+
+- Did the new run reflect the change you made?
+- Is the output more useful than before?
+- Did you improve the original problem without creating a new one?
+
+If yes, keep the change. If not, revert the change and try a different adjustment.
+
+If you want a stricter review loop, score each run for accuracy, completeness, and tone before you decide what to change next.
+
+## ✅ Checkpoint
+
+- [ ] I identified one specific problem from a real workflow run
+- [ ] I changed only one instruction or configuration detail before testing again
+- [ ] I ran `gh aw compile` after the edit and before triggering the next run
+- [ ] I committed both the workflow `.md` file and the regenerated `.lock.yml` file
+- [ ] I compared the new run with the previous run and decided what to change next
+
+<!-- journey: all -->
+**Next:** [What's Next? Keep Exploring](14-next-steps.md)
+<!-- /journey -->

workshop/README.md

@@ -26,6 +26,7 @@ A hands-on workshop that takes you from zero to a fully automated, AI-powered wo
 | 8 | [08-run-your-workflow.md](08-run-your-workflow.md) | Run and Watch Your Workflow | ✅ |
 | 8b | [08b-interpret-your-run.md](08b-interpret-your-run.md) | Interpret Your First Run | ✅ |
 | 9 | [09-agentic-editing.md](09-agentic-editing.md) | Refine Your Workflow with Agentic Editing | ✅ |
+| 12 | [12-test-and-iterate.md](12-test-and-iterate.md) | Test and Improve Your Workflow | ✅ |
 | 14 | [14-next-steps.md](14-next-steps.md) | What's Next? Keep Exploring | ✅ |
 | 15 | [15-conditional-logic.md](15-conditional-logic.md) | Make Your Workflow Smarter with Conditional Logic | ✅ |
 | 16 | [16-connect-data-source.md](16-connect-data-source.md) | Connect a Live Data Source to Your Workflow | ✅ |