docs: sort Prerequisites lists numerically ascending (#100)

Reorder the `## Prerequisites` bullets in 9 modules so prior modules
are listed lowest number first instead of by pedagogical importance or
at random. A trailing "Helpful but not required" group stays last and
is sorted within itself; multi-module bullets sort by their lowest
number. Intro/closing paragraphs are left in place. Prose is unchanged;
only bullet order moves.

Modules touched: 7, 9, 14, 15, 22, 24, 25, 26, 27. The other 18 modules
were already ascending (or have one/zero prereqs) and are untouched.
Module 19's "Helpful but not required: Module 16" correctly trails its
ascending 8/14/18 main list, so it stays as is.

Closes #100

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CamgR4HaVpfaqUViuHUcWw

modules/14-continuous-integration/README.md

@@ -8,13 +8,13 @@
 
 ## Prerequisites
 
+- **Module 2: Version Control.** Pushes, commits, and the diff habit are the substrate CI sits on.
 - **Module 8: Remotes and Hosting.** CI runs *on the forge*, triggered by pushes. You need a repo
   pushed to a remote (any forge: GitHub, GitLab, a self-hosted Forgejo/Gitea, whatever you set up
   in Module 8) for there to be anything to trigger.
 - **Module 13: Testing in the AI Era.** CI is mostly "run the tests, automatically." You need tests
   to run. If you skipped writing them, this module's lab ships a small suite so you're not blocked,
   but the real payoff is automating *your* tests.
-- **Module 2: Version Control.** Pushes, commits, and the diff habit are the substrate CI sits on.
 
 You do **not** need Docker, secrets management, or your own runner yet; those are Modules 16, 17,
 and 19. On a **SaaS forge** (GitHub, GitLab.com, Bitbucket, and the rest) this module uses the