Nachrichten: Design-Label, server-seitige Präferenz, mobiler Leerraum fix

backend/src/db.js

@@ -246,6 +246,11 @@ if (msgCols2.length && !msgCols2.includes('read_by_recipient')) {
   db.exec("ALTER TABLE messages ADD COLUMN read_by_recipient INTEGER NOT NULL DEFAULT 0");
 }
 
+// User-Preferences (JSON-Blob)
+const userCols2 = db.prepare("PRAGMA table_info(users)").all().map(r => r.name);
+if (!userCols2.includes('preferences'))
+  db.exec("ALTER TABLE users ADD COLUMN preferences TEXT DEFAULT NULL");
+
 // ── Login-Sicherheit ──────────────────────────────────────────────────────────
 // Spalten für Account-Lockout in users-Tabelle
 const userCols = db.prepare("PRAGMA table_info(users)").all().map(r => r.name);

backend/src/routes/auth.js

@@ -150,4 +150,20 @@ router.delete('/account', authenticate, (req, res) => {
   res.json({ success: true });
 });
 
+// ── GET/PUT /api/auth/preferences ─────────────────────────────────────────────
+router.get('/preferences', authenticate, (req, res) => {
+  const user = db.prepare('SELECT preferences FROM users WHERE id=?').get(req.user.id);
+  try { res.json(JSON.parse(user?.preferences || '{}')); }
+  catch { res.json({}); }
+});
+
+router.put('/preferences', authenticate, (req, res) => {
+  const user = db.prepare('SELECT preferences FROM users WHERE id=?').get(req.user.id);
+  let current = {};
+  try { current = JSON.parse(user?.preferences || '{}'); } catch {}
+  const merged = { ...current, ...req.body };
+  db.prepare('UPDATE users SET preferences=? WHERE id=?').run(JSON.stringify(merged), req.user.id);
+  res.json(merged);
+});
+
 module.exports = router;