feat: Speiseplan-Inhalte variabel mehrsprachig (Teil 2)

Gerichtnamen, Essenszeiten und Allergen-/Zusatzstoff-Bezeichnungen sind
jetzt genauso dynamisch mehrsprachig wie die Bedienoberfläche aus
v1.10.0, statt fest auf Englisch/Polnisch begrenzt zu sein. Neue
Übersetzungstabellen ersetzen die alten name_en/name_pl-Spalten,
DeepL-Auto-Übersetzung und CSV-Import/-Export unterstützen jetzt
beliebig viele aktive Sprachen.

app/api/dishes/[id]/route.ts

@@ -1,9 +1,18 @@
 import { NextResponse } from "next/server";
 import { query, queryOne } from "@/lib/db";
+import { loadTranslationsFor, replaceTranslations } from "@/lib/db/translations";
 import { authErrorResponse, requireRole } from "@/lib/auth/session";
 import { isSameOrigin } from "@/lib/origin";
 import type { Dish } from "@/lib/types";
 
+interface DishRow {
+  id: string;
+  name: string;
+  price: string;
+  allergens: string[];
+  additives: string[];
+}
+
 export async function PATCH(
   request: Request,
   { params }: { params: Promise<{ id: string }> }
@@ -16,19 +25,26 @@ export async function PATCH(
     const { id } = await params;
     const body = (await request.json()) as {
       name: string;
-      name_en: string | null;
-      name_pl: string | null;
       price: number;
       allergens: string[];
       additives: string[];
+      translations?: Record<string, string | null>;
     };
-    const dish = await queryOne<Dish>(
-      `update dishes set name = $1, name_en = $2, name_pl = $3, price = $4,
-              allergens = $5, additives = $6
-       where id = $7 returning *`,
-      [body.name, body.name_en, body.name_pl, body.price, body.allergens, body.additives, id]
+    const row = await queryOne<DishRow>(
+      `update dishes set name = $1, price = $2, allergens = $3, additives = $4
+       where id = $5 returning id, name, price, allergens, additives`,
+      [body.name, body.price, body.allergens, body.additives, id]
     );
-    if (!dish) return NextResponse.json({ error: "not_found" }, { status: 404 });
+    if (!row) return NextResponse.json({ error: "not_found" }, { status: 404 });
+    if (body.translations) {
+      await replaceTranslations("dish_translations", row.id, body.translations);
+    }
+    const translations = await loadTranslationsFor("dish_translations", [row.id]);
+    const dish: Dish = {
+      ...row,
+      price: Number(row.price),
+      translations: translations.get(row.id) ?? {},
+    };
     return NextResponse.json(dish);
   } catch (err) {
     const res = authErrorResponse(err);