feat: more role backend and admin/writer roles additions and adjustments

api/pkg/apperr/messages.go

@@ -24,7 +24,6 @@ const InviteNotFoundErrorMessage = "Invite not found"
 const InviteAlreadyAcceptedErrorMessage = "This invite has already been accepted."
 const InviteInvalidErrorMessage = "This invite link doesn't work."
 const InviteExpiredErrorMessage = "This invite has expired."
-const OwnerRequiredErrorMessage = "Only the owner can do this."
 const UsernameTakenErrorMessage = "That username is taken. Try another."
 const PasswordTooLongErrorMessage = "The password must be 72 bytes or fewer."
 const MediaQueryErrorMessage = "The media query is invalid."
@@ -39,8 +38,9 @@ const UpdateRestartMismatchErrorMessage = "The update state changed. Reload the
 const ArticleBodyFormatErrorMessage = "The format must be one of: markdown, html, json."
 const APIKeyNotFoundErrorMessage = "API key not found"
 const APIKeyExpiryErrorMessage = "The expiry must be a date in the future."
+const MissingPermissionErrorMessage = "missing_permission"
+const MissingPermissionHeader = "X-Missing-Permission"
 const SessionRequiredErrorMessage = "This action needs a real session."
-const OwnerOrAdminRequiredErrorMessage = "Only owners and admins can do this."
 const PurgeConflictErrorMessage = "The library changed, so nothing was purged. Check the new summary and try again."
 const PurgeBusyErrorMessage = "A purge is already running."
 const PurgeIntervalErrorMessage = "Enter a whole number of days between 1 and 365."