chore: centralize shared dependencies

We updated 8 hydrateWhen snapshot files in @tanstack/start-plugin-core to fix the test:unit failure caused by this PR's Babel upgrade (@babel/core ^7.28.5 → ^7.29.7, @babel/types ^7.28.5 → ^7.29.8). The newer Babel code generator emits dynamically-inserted JSX children ({<_Hx />}) and their closing tags (</Hydrate>) at column 0 instead of indented relative to the parent, so the stored snapshots no longer matched the actual compiler output. Updating the snapshots to reflect this formatting change restores the test suite to green.