feat: settings and deploy docs

app/settings/page.tsx

@@ -0,0 +1,39 @@
+import Link from "next/link";
+import { getDb } from "@/lib/db";
+import { DEFAULT_TAGE_VORHER } from "@/lib/settings";
+import { TestButtons } from "./test-buttons";
+
+export const dynamic = "force-dynamic";
+
+export default async function SettingsPage() {
+  const db = getDb();
+  const last = await db.notificationLog.findFirst({ orderBy: { sentAt: "desc" } });
+  return (
+    <main className="mx-auto max-w-xl space-y-4 p-6">
+      <Link href="/" className="text-sm underline">← Zurück</Link>
+      <h1 className="text-xl font-bold">Einstellungen</h1>
+      <section className="rounded border p-4">
+        <h2 className="font-medium">Standard-Erinnerungstage</h2>
+        <p className="text-sm text-gray-600">Neue Gutscheine erhalten diese Erinnerungsregeln: {DEFAULT_TAGE_VORHER.join(", ")} Tage vorher.</p>
+      </section>
+      <TestButtons />
+      <section className="rounded border p-4 text-sm">
+        <h2 className="font-medium">Letzter Cron-Lauf</h2>
+        {last ? (
+          <p>
+            {last.sentAt.toLocaleString("de-DE")} · {last.kanal} an {last.empfaenger} · {last.status}
+            {last.fehler ? ` · Fehler: ${last.fehler}` : ""}
+          </p>
+        ) : (
+          <p>Noch keine Benachrichtigung versendet.</p>
+        )}
+      </section>
+      <section className="rounded border p-4 text-sm text-gray-600">
+        <h2 className="font-medium text-black">Konfiguration (.env)</h2>
+        <p>SMTP_HOST, SMTP_PORT, SMTP_USER, SMTP_PASS, MAIL_FROM, TELEGRAM_BOT_TOKEN, CRON_SECRET, APP_URL.</p>
+        <h2 className="mt-2 font-medium text-black">Backup</h2>
+        <p>SQLite-Datei sichern: Volume <code>gutschein-data</code> bzw. Datei <code>/data/gutscheine.db</code> regelmäßig kopieren.</p>
+      </section>
+    </main>
+  );
+}

app/settings/test-buttons.tsx

@@ -0,0 +1,47 @@
+"use client";
+import { useState } from "react";
+
+export function TestButtons() {
+  const [mail, setMail] = useState("test@example.de");
+  const [chatId, setChatId] = useState("");
+  const [result, setResult] = useState("");
+
+  async function testMail() {
+    setResult("…");
+    const res = await fetch("/api/settings/test-mail", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: JSON.stringify({ to: mail }),
+    });
+    const data = await res.json().catch(() => ({}));
+    setResult(res.ok ? "Test-Mail versendet." : `Fehler: ${data.error ?? res.status}`);
+  }
+
+  async function testTelegram() {
+    setResult("…");
+    const res = await fetch("/api/settings/test-telegram", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: JSON.stringify({ chatId }),
+    });
+    const data = await res.json().catch(() => ({}));
+    setResult(res.ok ? "Test-Telegram versendet." : `Fehler: ${data.error ?? res.status}`);
+  }
+
+  return (
+    <section className="space-y-3 rounded border p-4">
+      <h2 className="font-medium">Versand testen</h2>
+      <div>
+        <label htmlFor="mail" className="block text-sm font-medium">E-Mail-Empfänger</label>
+        <input id="mail" value={mail} onChange={(e) => setMail(e.target.value)} className="mt-1 w-full rounded border px-3 py-2" />
+      </div>
+      <button type="button" onClick={testMail} className="rounded bg-black px-4 py-2 text-white">Test-Mail senden</button>
+      <div>
+        <label htmlFor="chatId" className="block text-sm font-medium">Telegram-Chat-ID</label>
+        <input id="chatId" value={chatId} onChange={(e) => setChatId(e.target.value)} className="mt-1 w-full rounded border px-3 py-2" />
+      </div>
+      <button type="button" onClick={testTelegram} className="rounded bg-black px-4 py-2 text-white">Test-Telegram senden</button>
+      {result && <p role="status" className="text-sm">{result}</p>}
+    </section>
+  );
+}