Restricted record names show FIELD_RESTRICTED_ADDITIONAL_PERMISSIONS_REQUIRED instead of "Not shared"

Problem When a calendar channel only shares metadata, the server replaces a calendar event's title with the FIELD_RESTRICTED_ADDITIONAL_PERMISSIONS_REQUIRED sentinel. The timeline card already renders that as "Not shared", but everything else that names a record (calendar view cards, relation chips, the side panel header) prints the raw sentinel. A week of colleagues' meetings reads as a column of error codes. Change Map the sentinel to "Not shared" in getLabelIdentifierFieldValue, which is where all of those surfaces read a record's name from. The string already exists in the catalog (ForbiddenFieldDisplay), so no new translation. Tests New getLabelIdentifierFieldValue.test.ts: plain value, restricted sentinel, and the record-id fallback without a label identifier field. Fix ready The change above is ready, with tests, on a fork: (single commit 9f39fe3ae2, on top of main). Opening pull requests here is limited to collaborators, so I could n…