M10: gloss /path/to/, git apply, and review-lab as throwaway (#53)

Module 10's lab embedded literal `/path/to/` placeholders and a first-use
`git apply` with no explanation, unlike the Module 1 exemplar. This adds the
course-wide "use your real course path in place of /path/to/" gloss (matching
M04/M07/M26), a half-sentence gloss on git apply, and a note that review-lab
is a throwaway repo separate from tasks-app.

Closes #53

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CfDmDAQL7xuSRm2L4qApvn

modules/10-reviewing-code-you-didnt-write/README.md

@@ -201,7 +201,10 @@ real change, then review a diff the "AI" produced and catch the trap planted in
 
 ### Part A — Open a PR as a gate
 
-1. Set up the base app as a repo and confirm its baseline behavior:
+1. Set up the base app as a repo and confirm its baseline behavior. This `review-lab` is a
+   throwaway repo *separate* from the `tasks-app` you've built up across earlier modules — you can
+   delete it when you're done, and nothing here touches your main app. (Use your real course path in
+   place of `/path/to/`, the same copy-it-in move from Module 5.)
 
    ```bash
    mkdir -p ~/workflow-course/review-lab && cd ~/workflow-course/review-lab
@@ -235,7 +238,10 @@ real change, then review a diff the "AI" produced and catch the trap planted in
 ### Part B — Review the AI's diff (the real exercise)
 
 3. Now a teammate-who-is-an-AI has opened a PR. The prompt it was given was exactly:
-   **"Add a `delete <index>` command to the tasks app."** Bring its change in on its own branch:
+   **"Add a `delete <index>` command to the tasks app."** Bring its change in on its own branch.
+   `git apply` lays the AI's proposed change onto this branch as if it were its PR, so you can read
+   it before deciding whether to keep it — exactly what you'd be doing in a real PR review. (Again,
+   use your real course path in place of `/path/to/`.)
 
    ```bash
    git switch main