fix(running-example): consistent lab-script paths, tasks.json policy, no command collisions

- Lab-script path convention: course scripts live in modules/NN/lab/; copy the
  one a step needs into tasks-app, then run by bare name (M4/M6/M7/M26 + headers).
- tasks.json stays gitignored: M20 verifies via `cli.py list`/`cat tasks.json`
  (not git diff) and frames runtime state as deliberately ignored; M22 cleanup
  uses `rm tasks.json`; M10 review-lab gets its own .gitignore.
  Module 21's lab deliberately ships NO .gitignore (teaching device) — untouched.
- Stop running-example command collisions: M5 clear->search, M6 count/clear->
  stats/purge, M7 clear/count->wipe/remaining (README + scripts + agent prompts +
  branch/worktree names). M6 conflict still reproduces on the carried usage line.

Closes #7
Closes #10
Closes #11

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TfzV5QvtPDz8LJS3Pu5VLT

modules/05-commit-the-ai-config/README.md

@@ -207,9 +207,11 @@ editor-integrated AI (Module 4) for the part where the AI obeys the file.
 ### Part B — Watch the AI obey it
 
 4. Start a **fresh** AI session in your editor (so it picks up the file cleanly) and give it a task
-   that the instructions constrain. For example:
+   that the instructions constrain. Pick a command your app doesn't have yet (so this is a real
+   feature, not a re-add) — for example:
 
-   > *"Add a `clear` command that removes all tasks. Then confirm it works."*
+   > *"Add a `search <term>` command that lists only the tasks whose title contains `term`. Then
+   > confirm it works."*
 
 5. Watch for the file taking effect. A correctly-configured agent should, without you saying any of
    it this time: