docs(readme): drop "!" from waitlist button, version-tag README images

- Regenerate assets/waitlist.svg as "Join the waitlist" (no exclamation),
  same cream/8px/padding styling.
- Add ?v=2 cache-buster to the README image URL so the new button shows
  immediately instead of waiting on GitHub's image cache.
- CLAUDE.md house rule: version-tag every README image and bump ?v=N in
  the same commit whenever the asset changes.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -263,3 +263,4 @@ publish actions on shared state. Write the files, hand the user the commands.
   - The **last main commit** — `git log --first-parent main -1 --format='%ai %h %s'`. A comment after the last release but before a fix on main may already be addressed there but unreleased.
   - The **current branch's tip** — your own unmerged work obviously can't be what the comment is reacting to.
   Always disambiguate "released," "merged-but-unreleased," and "in-progress" before agreeing that a user-reported problem is unfixed (or that a fix is incomplete). A user saying "your fix only covers X" about a recent PR is usually pointing at the *released* shortcomings — your in-flight branch may already address them but they have no way to know that.
+- **Version-tag every image referenced in `README.md`.** GitHub caches README images (`raw.githubusercontent.com` with a 5-minute TTL; third-party hosts sit behind the long-lived camo proxy), so updating an asset in place can keep showing the stale version. Give each README image URL a `?v=N` query tag and **bump `N` in the same commit whenever the asset bytes change** — e.g. `assets/waitlist.svg?v=2`. The changed URL sidesteps every cache so the new image shows immediately instead of waiting on a TTL to expire.

README.md

@@ -29,7 +29,7 @@
 
 **The CodeGraph platform is coming** — for every PR, know exactly what to test, what could break, which flows are affected, and whether business logic is compromised.
 
-<a href="https://getcodegraph.com"><img alt="Join the waitlist for early beta access" src="https://raw.githubusercontent.com/colbymchenry/codegraph/main/assets/waitlist.svg" height="52"></a>
+<a href="https://getcodegraph.com"><img alt="Join the waitlist for early beta access" src="https://raw.githubusercontent.com/colbymchenry/codegraph/main/assets/waitlist.svg?v=2" height="52"></a>
 
 <sub>Get <b>early beta access</b> to the hosted product · <a href="https://getcodegraph.com">getcodegraph.com</a></sub>