Server load redirects READ_ALL-only users (or unauthenticated) to /documents.
Page load: onMount reads bulkSelectionStore — redirects to /documents when the
store is empty, otherwise POSTs the IDs to /api/documents/batch-metadata and
hands the resulting summaries to BulkDocumentEditLayout in mode="edit".
Refs #225
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>