feature: a minimal v1 backend implemented for treatments feature.

frontend/src/components/ui/treatment/FdiToothChart.tsx

@@ -153,7 +153,7 @@ export function FdiToothChart({ selected, onToggle, disabled }: FdiToothChartPro
         <div>
           <h3 className="text-sm font-semibold text-text-primary">FDI tooth chart</h3>
           <p className="text-xs text-text-muted mt-0.5">
-            Tap teeth to multi-select (FDI). Selection applies to the active treatment record until you save.
+            Tap teeth to multi-select (FDI). Selection applies to the active treatment case until you save.
           </p>
         </div>
         <div className="flex flex-col gap-2 sm:items-end w-full sm:max-w-xs">