Fix authentication state consistency across components

- Fix ChatInterface to use context's reactive isAuthenticated value
- Fix useAgentLoop to use context's reactive isAuthenticated value
- Ensure consistent authentication state checking across the application
- Add isAuthenticated to useCallback dependencies for proper reactivity

🤖 Generated with [Claude Code](https://claude.ai/code)

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

src/components/ChatInterface.tsx

@@ -16,7 +16,7 @@ export function ChatInterface() {
     getAgentLoopState,
   } = useConversation();
   
-  const { currentProvider } = useInference();
+  const { provider: currentProvider, isAuthenticated } = useInference();
   const [isLoading, setIsLoading] = useState(false);
   const messagesEndRef = useRef<HTMLDivElement>(null);