Hoist five duplicated helpers into single source modules so each
contract evolves in exactly one place:
- src/lib/api/read-error.ts — replaces the four hand-rolled copies
in the onboarding flow (Welcome / Goals / Source / Baseline).
- src/lib/medications/research-mode-types.ts — shared ResearchModeStatus
DTO + tri-state gate helper consumed by both the DrugLevelChart
and the Settings advanced section.
- src/lib/medications/route-guards.ts — assertMedicationOwnership
for the eleven medication sub-routes, preserving the 404 leak
shape across the privacy boundary.
- src/lib/medications/dose-string.ts — unified parseDoseMg + null
variant replacing the DrugLevelChart and titration-route parsers.
- src/lib/medications/glp1-knowledge.ts — adds findDrugIdByBrand
reverse lookup so the brand-to-id pattern stops being open-coded
at every chart render.
28 new unit tests across the five helpers.
