Add web Prettier formatting reminder to CLAUDE.md

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: bfirsh

CLAUDE.md

@@ -7,6 +7,7 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 - `npm test` - Run code formatting check and tests (required before commits)
 - `npm run build` - Build distribution files (`dist/jsnes.js` and `dist/jsnes.min.js`)
 - `npm run format` - Auto-format all source code with Prettier
+- `cd web && npx prettier --write src/` - Format web UI code (web has its own Prettier config; `npm run format` only covers `src/`)
 - `npm run test:watch` - Run tests in watch mode for development
 - `npm run typecheck` - TypeScript type checking (verifies `.d.ts` files)
 - `node bench.js` - Run performance benchmark (~1800 fps baseline). Run this on major changes or when you suspect a performance regression/improvement.