Add AGENTS.md note to avoid running dev server

AGENTS.md

@@ -72,6 +72,39 @@ pnpm lint
 
 This ensures all code follows the project's formatting standards, type safety requirements, and linting rules, preventing issues in pull requests.
 
+### CRITICAL: Never Run Dev Servers
+
+**DO NOT run development servers (e.g., `npm run dev`, `pnpm dev`, `next dev`) as they will conflict with other running instances.**
+
+#### Why This Rule Exists:
+- Dev servers run indefinitely and block the terminal session
+- Multiple instances on the same port cause conflicts
+- The application may already be running in the user's environment
+- Long-running processes make the conversation hang for the user
+
+#### Commands to AVOID:
+```bash
+# DO NOT RUN THESE:
+npm run dev
+pnpm dev
+next dev
+npm start
+pnpm start
+yarn dev
+node --watch
+nodemon
+```
+
+#### What to Do Instead:
+1. **Testing changes**: Use `pnpm build` to verify the production build works
+2. **Type checking**: Use `pnpm type-check` to verify types
+3. **Linting**: Use `pnpm lint` to check code quality
+4. **Running tests**: Use `pnpm test` if tests are available
+5. **If the user needs to test**: Let the user run the dev server themselves
+
+#### Exception:
+If the user explicitly asks you to start a dev server, politely explain why you cannot do this and suggest they run it themselves instead.
+
 ### Logging Best Practices
 
 1. **Use descriptive static messages**