Modal rendering workflow + signers + events for a signed-PDF file.
Wired to GET /api/v1/documents/[id]/signing-details. The "view signing
details" link on signed-file rows in the Files section opens this
dialog (wiring in the entity-folder view task).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
