Add allowPublicCompletedDocumentAccess toggle at org/team level
(team inherits from org via null). Recipients see a "View completed
PDF" button on the signing completion page that links to /share/qr_*.
- DB migration adding toggle to OrganisationGlobalSettings and TeamGlobalSettings
- Settings UI for org and team document preferences
- Rate limiting on QR share view and file download endpoints
- Structured error responses with support codes in share route ErrorBoundary
- Exponential backoff retry when qrToken not yet available post-completion
- QR-authenticated viewers restricted to signed PDF only (no original)
- E2E tests covering happy path, not-yet-completed, invalid token, and toggle revocation