Whether a title came from the MAIDR JSON rather than a model placeholder
default the Figure / Trace models substitute when the JSON omits title.
Blank / whitespace-only titles also count as unauthored, since announcing a
bare label like "Title is " is not useful.
Single source of truth for the placeholder-rejection rule, shared by
Context.isAuthoredTitle, TextService, and the subplot cue
builders so the rule cannot drift across copies.
Known limitation: a title authored as the exact placeholder string
(e.g. "MAIDR Plot" or "unavailable") is filtered out; the sentinel defaults
are deliberately uncommon strings to minimize collision risk.
Whether a title came from the MAIDR JSON rather than a model placeholder default the Figure / Trace models substitute when the JSON omits
title. Blank / whitespace-only titles also count as unauthored, since announcing a bare label like "Title is " is not useful.Single source of truth for the placeholder-rejection rule, shared by Context.isAuthoredTitle, TextService, and the subplot cue builders so the rule cannot drift across copies.
Known limitation: a title authored as the exact placeholder string (e.g. "MAIDR Plot" or "unavailable") is filtered out; the sentinel defaults are deliberately uncommon strings to minimize collision risk.