Bring the codebase in line with CLAUDE.md conventions

- Convert getRouter, OrderingPage, and OrderStatusRoute from function
  declarations to arrow functions
- Migrate header-user.tsx off raw Tailwind classes onto a co-located
  SCSS module, and remove Tailwind entirely (deps, Vite plugin,
  styles.css) since it was the only consumer and duplicated the
  documented SCSS Modules system
- Fix CLAUDE.md's stale ~/ alias example and structure diagram to
  match the project's actual #/ and @/ aliases and directories

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

vite.config.ts

@@ -4,11 +4,10 @@ import { devtools } from '@tanstack/devtools-vite'
 import { tanstackStart } from '@tanstack/react-start/plugin/vite'
 
 import viteReact from '@vitejs/plugin-react'
-import tailwindcss from '@tailwindcss/vite'
 
 const config = defineConfig({
   resolve: { tsconfigPaths: true },
-  plugins: [devtools(), tailwindcss(), tanstackStart(), viteReact()],
+  plugins: [devtools(), tanstackStart(), viteReact()],
 })
 
 export default config