fix(collections): validate virtual fields in useAsTitle for auth collections (#16142)

[deepshekhardas]

Fixes #16142 - useAsTitle virtual field validation is skipped if collection has auth enabled

Problem: Virtual field validation was being skipped for auth-enabled collections, allowing virtual fields to be used as title which breaks relationship searching

Solution: Moved virtual field validation outside the auth check so it applies to all collections

[github-actions]

Pull Request titles must follow the Conventional Commits specification and have valid scopes.

Unknown scope "collections" found in pull request title "fix(collections): validate virtual fields in useAsTitle for auth collections (#16142)". Scope must match one of: cpa, claude, db-*, db-d1-sqlite, db-mongodb, db-postgres, db-vercel-postgres, db-sqlite, db-d1-sqlite, drizzle, email-*, email-nodemailer, email-resend, eslint, graphql, kv, kv-redis, live-preview, live-preview-react, live-preview-vue, next, payload-cloud, plugin-cloud, plugin-cloud-storage, plugin-ecommerce, plugin-form-builder, plugin-import-export, plugin-mcp, plugin-multi-tenant, plugin-nested-docs, plugin-redirects, plugin-search, plugin-sentry, plugin-seo, plugin-stripe, richtext-*, richtext-lexical, richtext-slate, sdk, storage-*, storage-azure, storage-gcs, storage-r2, storage-uploadthing, storage-vercel-blob, storage-s3, translations, ui, templates, examples(/(\w|-)+)?, deps.

feat(ui): add Button component
^    ^    ^
|    |    |__ Subject
|    |_______ Scope
|____________ Type