該当エラーは直しました。

frontend/src/app/rice-transplant/_components/RiceTransplantEditPage.tsx に Variety 型の import を追加して、find のコールバック引数に明示型を付けています。今回の Parameter 'variety' implicitly has an 'any' type はこれで解消するはずです。

そのままもう一度 npm run build を回してみてください。もし次の型エラーが出たら、続けて直します。

frontend/src/app/rice-transplant/_components/RiceTransplantEditPage.tsx

@@ -6,7 +6,7 @@ import { ChevronLeft, Save } from 'lucide-react';
 
 import Navbar from '@/components/Navbar';
 import { api } from '@/lib/api';
-import { Crop, Field, RiceTransplantPlan, StockSummary } from '@/types';
+import { Crop, Field, RiceTransplantPlan, StockSummary, Variety } from '@/types';
 
 type BoxMap = Record<number, string>;
 
@@ -39,9 +39,9 @@ export default function RiceTransplantEditPage({ planId }: { planId?: number })
 
   const years = Array.from({ length: 5 }, (_, i) => currentYear + 1 - i);
 
-  const allVarieties = crops.flatMap((crop) => crop.varieties);
+  const allVarieties = crops.flatMap((crop: Crop) => crop.varieties);
   const getVarietyBySeedMaterial = (id: number) =>
-    allVarieties.find((variety) => variety.seed_material === id) ?? null;
+    allVarieties.find((variety: Variety) => variety.seed_material === id) ?? null;
 
   const calculateDefaultBoxes = (field: Field, perTan: string) => {
     const areaTan = parseFloat(field.area_tan || '0');
@@ -67,7 +67,7 @@ export default function RiceTransplantEditPage({ planId }: { planId?: number })
           const plan: RiceTransplantPlan = planRes.data;
           const fetchedVarieties = cropsRes.data.flatMap((crop: Crop) => crop.varieties);
           const linkedVariety =
-            fetchedVarieties.find((variety) => variety.id === plan.variety) ?? null;
+            fetchedVarieties.find((variety: Variety) => variety.id === plan.variety) ?? null;
           setName(plan.name);
           setYear(plan.year);
           setSeedMaterialId(linkedVariety?.seed_material ?? '');