A `from` union should result in a intersection of relative `to` paths

Which project does this relate to?

Router

Describe the bug

When from is a union of different paths, to allows a union of relative paths for from instead of an intersection, resulting in invalid links.

Your Example Website or App

https://stackblitz.com/edit/github-dj5qylfv?file=src%2FPage.tsx,src%2Froutes%2F__root.tsx,src%2Froutes%2Fposts%2Fpost%2F%24postId.tsx,src%2Froutes%2Fusers%2Fuser%2F%24userId.tsx

Steps to Reproduce the Bug or Issue

1. Use a from that is an union of different valid paths
2. Write a relative to

Expected behavior

to should only allow relative paths that are valid for all from paths.

Screenshots or Videos

No response

Platform

• OS: Windows
• Browser: Chrome
• Version: 131.0.6778.140

Additional context

I wonder if this can be done in TS 🤔

Start with the linked StackBlitz reproduction and the referenced files: src/Page.tsx, src/routes/__root.tsx, src/routes/posts/post/$postId.tsx, and src/routes/users/user/$userId.tsx. Reproduce a relative to with a union-valued from, then trace the router's TypeScript path types. Done means invalid relative paths are rejected when they are not valid for every from path.