feat: Implement comprehensive member management with user accounts, roles, and password handling for admin and mobile applications.

innungsapp/apps/admin/app/[slug]/dashboard/mitglieder/[id]/page.tsx

@@ -119,6 +119,7 @@ export default function MitgliedEditPage({
               <div>
                 <label className="block text-sm font-medium text-gray-700 mb-1">Sparte</label>
                 <select value={form.sparte} onChange={(e) => setForm({ ...form, sparte: e.target.value })} className={inputClass}>
+                  <option value="">— Bitte wählen —</option>
                   {SPARTEN.map((s) => <option key={s}>{s}</option>)}
                 </select>
               </div>