feat(cms): implement multi-language support across frontend and admin UI

apps/backend/src/routes/products.ts

@@ -4,9 +4,47 @@ import prisma from "../lib/prisma";
 export const productsRoute = new Elysia({ prefix: "/products" })
   .get("/scents", async () => {
     return await prisma.scent.findMany({
-      orderBy: { name: "asc" }
+      orderBy: { name: "asc" },
+      include: { translations: true }
     });
   })
+  .patch("/scents/:id/translations", async ({ params, body, status }) => {
+    const id = parseInt(params.id);
+    if (isNaN(id)) return status(400, { message: "Invalid scent ID" });
+
+    const payload = body as any;
+    const results: any[] = [];
+    const LANGS = ['th', 'en', 'ja', 'zh', 'vi', 'ko'];
+
+    for (const lang of LANGS) {
+      const name = typeof payload.name === 'string' ? (lang === 'th' ? payload.name : null) : payload.name?.[lang];
+      if (!name) continue;
+
+      const existing = await prisma.scentTranslation.findUnique({
+        where: { scentId_langCode: { scentId: id, langCode: lang } }
+      });
+
+      if (existing) {
+        const updated = await prisma.scentTranslation.update({
+          where: { id: existing.id },
+          data: { name },
+        });
+        results.push(updated);
+      } else {
+        const created = await prisma.scentTranslation.create({
+          data: { scentId: id, langCode: lang, name },
+        });
+        results.push(created);
+      }
+    }
+
+    const updated = await prisma.scent.findUnique({
+      where: { id },
+      include: { translations: true },
+    });
+
+    return { success: true, translations: results, scent: updated };
+  })
   .get("/", async ({ query }) => {
     const categoryId = query.categoryId ? parseInt(query.categoryId) : undefined;
     const scentId = query.scentId ? parseInt(query.scentId) : undefined;