refactor: move person domain components and utils to lib/person/

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/routes/documents/[id]/+page.server.ts

@@ -1,7 +1,7 @@
 import { error, redirect } from '@sveltejs/kit';
 import { createApiClient } from '$lib/api.server';
 import { getErrorMessage } from '$lib/errors';
-import { inferredRelationshipLabel } from '$lib/relationshipLabels';
+import { inferredRelationshipLabel } from '$lib/person/relationshipLabels';
 
 export async function load({ params, fetch }) {
 	const { id } = params;