Fix ESLint fast-refresh warnings

Refactor to resolve react-refresh/only-export-components warnings:
- Move buttonVariants export to separate file (Button.variants.ts)
- Extract WebSocketContext to dedicated context file
- Move useWebSocketContext hook to separate file
- Update imports across affected files

All component files now export only components, improving fast refresh reliability

src/components/primitives/Button/Button.tsx

@@ -100,5 +100,3 @@ function LoadingSpinner() {
     </svg>
   );
 }
-
-export { buttonVariants, type ButtonVariants };

src/components/primitives/Button/index.ts

@@ -1 +1,2 @@
-export { Button, type ButtonProps, buttonVariants, type ButtonVariants } from './Button';
+export { Button, type ButtonProps } from './Button';
+export { buttonVariants, type ButtonVariants } from './Button.variants';