📝 docs(commands): update development commands from npm to pnpm

- replace all npm commands with pnpm equivalents
- update build and run instructions to use pnpm package manager

CLAUDE.md

@@ -5,11 +5,11 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 ## Development Commands
 
 **Build and Run:**
-- `npm run dev` - Start development server on port 8080
-- `npm run build` - Build both client and server
-- `npm run build:client` - Build client only
-- `npm run build:server` - Build server only
-- `npm start` - Start production server
+- `pnpm run dev` - Start development server on port 8080
+- `pnpm run build` - Build both client and server
+- `pnpm run build:client` - Build client only
+- `pnpm run build:server` - Build server only
+- `pnpm start` - Start production server
 
 **Database:**
 - MySQL database runs on localhost:3306 (default credentials: root/empty)