Returns the bearer Person's notification inbox. Person-scoped: X-Wingspan-Account is rejected with 400 AccountScopeNotApplicable (Account context is the ?filter[subjectAccountId][eq]= filter, not the header). Cross-Person access is masked as 404 ResourceNotFound. Default filter when filter[status][anyOf] is omitted: Active,Viewed (non-dismissed). Inbox-visibility rule: only notifications whose InApp delivery reached Sent/Delivered are listed. Results are ordered newest-first (-createdAt); there is no sort parameter (fixed -createdAt ordering). Unread count = this endpoint with ?filter[status][anyOf][]=Active, reading pagination.totalSize.