/**
 * Wraps a class instance in a reactive proxy for use inside React components.
 * Whenever you read a field decorated with `@observable`, the hook
 * automatically subscribes to changes on that specific field, so your component
 * only re-renders when the values you actually access are updated.
 *
 * Under the hood, `useObserved` returns a Proxy of your object. It tracks
 * property reads during render and sets up listeners for those keys.
 * When one of those keys changes, the hook forces the component to re-render.
 *
 * Usage:
 * ```typescript
 * class Counter {
 *   @observable accessor count: number = 0;
 *
 *   increment() {
 *     this.count++;
 *   }
 * }
 *
 * const c = new Counter();
 *
 * const CounterCompo = () => {
 *   // Only `count` reads will be tracked
 *   const { count } = useObserved(counter);
 *
 *   return (
 *     <div>
 *       <button onClick={() => counter.increment()}>+1</button>
 *       <p>{count}</p>
 *     </div>
 *   );
 * };
 * ```
 */
export declare function useObserved<T extends object>(target: T): T;