node_added already fires once per node as it enters the tree (including
every descendant of a newly-added subtree), so the recursive call_deferred
in _on_node_added was redundant and held a raw Node reference across a
frame boundary. If that node got freed before the deferred call fired
(e.g. a container torn down and rebuilt the same frame), the engine's
message queue couldn't marshal the argument and threw "Cannot convert
argument 1 from Object to Object". Wiring synchronously removes the
window entirely.
Also silences the intentional integer division in _duration_text,
matching the same annotation already applied to _elapsed_simulated_text.
Renames locals/params that shadowed base-class properties (Node.name,
Control.size, BoxContainer.alignment), prefixes an intentionally-unused
parameter, and annotates a deliberate integer division so the console
stays clean during development.
Local user://settings.cfg meant zoom level didn't follow a student
across devices/browsers. Question bank and CCS text scale now live on
the user's study profile in Mongo (QuestionTextScale/CcsTextScale),
synced through a new PUT /api/profile/me/text-scale endpoint and the
existing preferences GET/cache already used for study preferences.
Both question_player.gd and ccs_service.gd read the synced value at
startup and react to AccountProfileService.profile_changed so a value
pulled down after login (or changed from another session) applies
without a restart. Backend validates the 0.85-1.35 range and updates
only the field(s) provided via a targeted $set, so it can't clobber
the other scale or the unrelated study-profile preferences.