Three additive migrations the v1.18.1 feature surfaces build on:
reminder engine fields (endsOn + origin, so coach-cadence and preventive
care produce into one reminder table), a user-scoped biomarker catalog
(name, unit, bounds, optional encrypted context, panel) with a nullable
LabResult.biomarkerId link, and the condition-journal model (IllnessEpisode
plus a CycleDayLog-shaped symptom timeline). No code consumes these yet;
the surfaces ship gated behind the module system.
