@tanstack/start-server-core exporting type from devDependency

[tsmithhisler]

Which project does this relate to?

Start

Describe the bug

The function getRequestHeaders() is explicitly typed to return TypedHeaders<RequestHeaderMap>. Both of these types are imported from the package fetchdts which is listed as a devDependency.

ref:
getRequestHeaders() - (https://github.com/TanStack/router/blob/main/packages/start-server-core/src/request-response.ts#L160)

Your Example Website or App

https://github.com/tsmithhisler/tanstack-start-7316

Steps to Reproduce the Bug or Issue

• Checkout https://github.com/tsmithhisler/tanstack-start-bug
• run pnpm install
• run pnpm run repro

Expected behavior

The linter should not warn me of no unsafe assignment when calling getRequestHeaders().

Screenshots or Videos

No response

Platform

• Router / Start Version: [e.g. 1.121.0] @tanstack/start-server-core@1.167.19
• OS: [e.g. macOS, Windows, Linux] Linux
• Browser: [e.g. Chrome, Safari, Firefox] N/A
• Browser Version: [e.g. 91.1] N/A
• Bundler: [e.g. vite] vite
• Bundler Version: [e.g. 7.0.0] 8.0.8

Additional context

No response