ValidateLinkOptions throwing type error when trying to add search params through function.

Which project does this relate to?

Router

Describe the bug

The search option is throwing a type error when trying to setup linkOptions props. While the code navigates properly, the type is

Your Example Website or App

https://stackblitz.com/edit/tanstack-router-4gmm6ikn?file=src%2Froutes%2Fabout.tsx

Steps to Reproduce the Bug or Issue

Go to About page in code,
Hover type error on

<HeadingLink
  title="Three"
  linkOptions={{
    to: '/posts',
    search: (prev) => ({ ...prev, tag: 'three' }),
  }}
/>
```



### Expected behavior

I expect the search options to work with typesafety as 'to' 'from' etc do

### Screenshots or Videos

_No response_

### Platform

- Router / Start Version: 1.132.47
- OS: MacOS
- Browser: Chrome
- Bundler: vite
- Bundler Version: 7.1.7


### Additional context

_No response_

Start with the About page in the linked StackBlitz reproduction and inspect the HeadingLink linkOptions example, then trace the ValidateLinkOptions type involved in the hover error. Reproduce the type error for the search callback while confirming navigation still works. Done means the callback is accepted with type safety like the to and from options.