Implants heading + list — only present when at least one implant exists.
2.2.1: per-tooth free-text notes — one "<tooth>: <note>" line per tooth
that carries a note (gated on the notes-enabled setting, like the tooltip).
null when no tooth has a note, so the panel/PDF omit the section entirely.
R2-B Task 2: the status->plan diff (see getPlanChanges), verbatim.
[] whenever the plan chart hasn't been initialized or plan === status —
a distinct field, not a section, since it's a diff rather than a status
list. The "What changes" box in App.tsx renders from this field only
when it's non-empty.
Structured, already-localized textual summary of the whole odontogram.