feat: CSV-Import/-Export für Gerichte/Allergene/Zusatzstoffe, RSS-Fix für mehrere Essenszeiten

CSV-Import/-Export (Gerichte, Allergene, Zusatzstoffe): neue Export-/
Import-Routen unter app/api/*/export und */import, hand-geschriebener
CSV-Parser/-Serializer (lib/csv.ts, keine neue Abhängigkeit), Upsert
über Kürzel (Allergene/Zusatzstoffe) bzw. exakten Namen (Gerichte,
mit Ambiguitäts-Check bei Namensdopplung). UI-Buttons in DishManager
und CodeListManager.

RSS-Feed: <content:encoded> zusätzlich zu <description> ausgeben,
da mehrere Feed-Reader description als kürzbare Vorschau behandeln
und dadurch bei mehreren Essenszeiten pro Tag nur die erste zeigten.

Version 1.7.0.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

app/api/allergens/export/route.ts

@@ -0,0 +1,24 @@
+import { listCodes } from "@/lib/db/code-lists";
+import { authErrorResponse, requireRole } from "@/lib/auth/session";
+import { toCsv } from "@/lib/csv";
+
+export async function GET() {
+  try {
+    await requireRole(["staff", "admin"]);
+    const items = await listCodes("allergens");
+    const rows = [
+      ["code", "name", "name_en", "name_pl"],
+      ...items.map((i) => [i.code, i.name, i.name_en ?? "", i.name_pl ?? ""]),
+    ];
+    return new Response(toCsv(rows), {
+      headers: {
+        "Content-Type": "text/csv; charset=utf-8",
+        "Content-Disposition": 'attachment; filename="allergene.csv"',
+      },
+    });
+  } catch (err) {
+    const res = authErrorResponse(err);
+    if (res) return res;
+    throw err;
+  }
+}

app/api/allergens/import/route.ts

@@ -0,0 +1,53 @@
+import { NextResponse } from "next/server";
+import { importCodes, type CodeImportRow } from "@/lib/db/code-lists";
+import { authErrorResponse, requireRole } from "@/lib/auth/session";
+import { isSameOrigin } from "@/lib/origin";
+import { parseCsvWithHeader } from "@/lib/csv";
+
+export async function POST(request: Request) {
+  if (!isSameOrigin(request)) {
+    return NextResponse.json({ error: "Nicht erlaubt." }, { status: 403 });
+  }
+  try {
+    await requireRole(["staff", "admin"]);
+    const form = await request.formData();
+    const file = form.get("file");
+    if (!(file instanceof File)) {
+      return NextResponse.json({ error: "invalid_input" }, { status: 400 });
+    }
+
+    const { header, rows: cells } = parseCsvWithHeader(await file.text());
+    const codeIdx = header.indexOf("code");
+    const nameIdx = header.indexOf("name");
+    if (codeIdx === -1 || nameIdx === -1) {
+      return NextResponse.json({ error: "missing_columns" }, { status: 400 });
+    }
+    const nameEnIdx = header.indexOf("name_en");
+    const namePlIdx = header.indexOf("name_pl");
+
+    const rows: CodeImportRow[] = [];
+    const skipped: { row: number; reason: string }[] = [];
+    cells.forEach((c, i) => {
+      const rowNum = i + 2; // 1-indexiert + Kopfzeile
+      const code = (c[codeIdx] ?? "").trim();
+      const name = (c[nameIdx] ?? "").trim();
+      if (!code || !name) {
+        skipped.push({ row: rowNum, reason: "Kürzel oder Bezeichnung fehlt" });
+        return;
+      }
+      rows.push({
+        code,
+        name,
+        name_en: nameEnIdx >= 0 ? c[nameEnIdx]?.trim() || null : null,
+        name_pl: namePlIdx >= 0 ? c[namePlIdx]?.trim() || null : null,
+      });
+    });
+
+    const result = rows.length > 0 ? await importCodes("allergens", rows) : { created: 0, updated: 0 };
+    return NextResponse.json({ ...result, skipped });
+  } catch (err) {
+    const res = authErrorResponse(err);
+    if (res) return res;
+    throw err;
+  }
+}