[Bug]: faliure to declare custom routes

[guaijie]

What version of React Router are you using?

6.4.3

Steps to Reproduce

type RouteHandle = { foo?: string }

interface FooRoute extends Omit<RouteObject, 'children'> {
  handle?: RouteHandle 
  children?: FooRoute[]
};

const myRoutes: FooRoute[] = [
  {
    path: '/home',
    element: <h1>Home</h1>,
    handle: { foo: 'bar' }
  },
  {
    path: '/anotherPage',
    element: <h1>Another page</h1>,
    handle: { foo: 'somethingElse' }
  },
]

//  1. The type of the attribute "index" is incompatible. Cannot assign type "true" to type "false"
const router = createBrowserRouter(routes)

// 2. I defined RouteHandle this way, but there is no type inference when using useMatches
export declare function useMatches(): {
    id: string;
    pathname: string;
    params: Params<string>;
    data: unknown;
    handle: unknown;  //  why unknown ?
}[];

const matches= useMatches()
const handle = useMatches().at(-1)?.handle as Handle  // we need to cast it to get at them

Expected Behavior

Hopefully, I can define route type in this way

Actual Behavior

I cannot define route type in this way

[timdorr]

#9427 (comment)