Add build PR instructions

Author: Buster-Darragh-Major

CLAUDE.md

@@ -20,3 +20,15 @@ When implemented, this will likely be a GitHub Action with:
 - CI/CD workflows in `.github/workflows/`
 - Documentation in `README.md` files
 - Linting with ESLint and Prettier
+
+## Pull Request Workflow
+
+When raising a PR, follow these steps to ensure the "check dist is up to date" build step passes:
+
+1. Rebase on main: `git rebase main`
+2. Install dependencies: `yarn install`
+3. Build the distribution: `yarn build`
+4. Commit the changes to `dist/` if any files were updated
+5. Push the branch and create the PR
+
+This ensures the built distribution files in `dist/` are always up to date with the source code.