PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://refine.dev/docs/guides-concepts/contributing/#commit-convention

Bugs / Features

• Related issue(s) linked
• Tests for the changes have been added
• Docs have been added / updated
• Changesets have been added https://refine.dev/docs/guides-concepts/contributing/#creating-a-changeset

What is the current behavior?

Refine does not provide an official TanStack Router integration package.
There is no dedicated TanStack Router integration page, and the routing guide/examples do not cover TanStack Router.

What is the new behavior?

This PR adds an initial @refinedev/tanstack-router package with Refine router-provider support for TanStack Router.

It includes:

• a new TanStack Router integration package
• route-aware helpers such as NavigateToResource, CatchAllNavigate, DocumentTitleHandler, and UnsavedChangesNotifier
• TanStack Router documentation under the routing integrations docs
• TanStack Router examples in the routing guide
• routing tutorial pages for the TanStack Router flow
• a changeset for publishing @refinedev/tanstack-router

Related: #6919

Notes for reviewers

• Added packages/tanstack-router modeled on packages/react-router.
• Added package tests and updated docs to surface the new integration.
• Added a changeset for @refinedev/tanstack-router.
• The TanStack Router tutorial pages are included, but they are not wired into the main tutorial selector flow in this PR.
• I could not run the normal install/test flow in this environment because the local Node/npm/pnpm toolchain was unstable, so pnpm-lock.yaml was patched manually from published package metadata.