Deterministic main branch + fix two claims (#5,#13,#16) (#56)

Co-authored-by: claude <claude@jpaul.io>
Co-committed-by: claude <claude@jpaul.io>

modules/08-remotes-and-hosting/README.md

@@ -119,8 +119,9 @@ the "someone else" was the host's auto-generated README.)
 **3. Branch-name mismatch.** Your local default branch is `master` but the host expects `main` (or
 vice versa). `git push -u origin main` then errors with `src refspec main does not match any`. Fix:
 check what you actually have with `git branch`, and either push the branch you have
-(`git push -u origin master`) or rename it first (`git branch -m main`). Worth settling early so it
-doesn't confuse you for the rest of the course.
+(`git push -u origin master`) or rename it first (`git branch -m main`). If you initialized with
+`git init -b main` back in Module 2, you're already on `main` and this one won't bite you here — but
+it's the classic wall for any repo that started life on `master`, so it's worth recognizing.
 
 ### Pull, fetch, and the everyday loop