feat: add admin user management (create, password change)

app/admin/components/UserForm.tsx

@@ -0,0 +1,78 @@
+'use client';
+
+import React, { useState } from 'react';
+import { createAdmin, updateAdminPassword } from '../actions';
+
+interface UserFormProps {
+  initialData?: any;
+  onClose: () => void;
+}
+
+export default function UserForm({ initialData, onClose }: UserFormProps) {
+  const [loading, setLoading] = useState(false);
+
+  async function handleSubmit(formData: FormData) {
+    setLoading(true);
+    if (initialData) {
+      await updateAdminPassword(initialData.id, formData);
+    } else {
+      await createAdmin(formData);
+    }
+    setLoading(false);
+    onClose();
+  }
+
+  return (
+    <div className="modal-overlay">
+      <div className="modal-content">
+        <div className="card-header">
+          <h2 className="card-title">{initialData ? 'Şifre Değiştir' : 'Yeni Admin Ekle'}</h2>
+          <button onClick={onClose} className="action-btn">✕</button>
+        </div>
+        <form action={handleSubmit} className="admin-form">
+          {!initialData && (
+            <div className="form-group">
+              <label htmlFor="username">Kullanıcı Adı</label>
+              <input
+                id="username"
+                name="username"
+                className="admin-input"
+                placeholder="Örn: ayrisdev"
+                required
+              />
+            </div>
+          )}
+          {initialData && (
+            <div className="form-group">
+              <label>Kullanıcı Adı</label>
+              <input
+                className="admin-input"
+                value={initialData.username}
+                disabled
+                style={{ opacity: 0.6 }}
+              />
+            </div>
+          )}
+          <div className="form-group">
+            <label htmlFor="password">{initialData ? 'Yeni Şifre' : 'Şifre'}</label>
+            <input
+              id="password"
+              name="password"
+              type="password"
+              className="admin-input"
+              required
+            />
+          </div>
+          <div style={{ display: 'flex', gap: '1rem', marginTop: '1rem' }}>
+            <button type="submit" className="admin-btn" disabled={loading}>
+              {loading ? 'Kaydediliyor...' : 'Kaydet'}
+            </button>
+            <button type="button" onClick={onClose} className="admin-btn" style={{ background: 'rgba(255,255,255,0.05)', color: '#fff' }}>
+              İptal
+            </button>
+          </div>
+        </form>
+      </div>
+    </div>
+  );
+}