Flutter: tampilkan URL server tersimpan saat layar login berikutnya

- Session.clear() kini hapus sesi (user/pass) tapi sisakan URL terakhir
- + Session.readLastUrl()
- LoginScreen mengisi field URL dari URL terakhir saat dibuka
- sesudah logout login lagi URL sudah terisi, tak perlu ketik ulang

flutter/lib/main.dart

@@ -96,6 +96,19 @@ class _LoginScreenState extends State<LoginScreen> {
   bool _busy = false;
   String? _error;
 
+  @override
+  void initState() {
+    super.initState();
+    _loadUrl();
+  }
+
+  Future<void> _loadUrl() async {
+    final url = await Session.readLastUrl();
+    if (url != null && mounted) {
+      setState(() => _url.text = url);
+    }
+  }
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(

flutter/lib/services/session.dart

@@ -27,9 +27,12 @@ class Session {
   }
 
   static Future<void> clear() async {
-    await _storage.delete(key: _kBase);
-    await _storage.delete(key: _kDb);
+    // Hapus sesi (user & pass), tapi sisakan URL (_kBase) agar login berikutnya mudah
     await _storage.delete(key: _kUser);
     await _storage.delete(key: _kPass);
   }
+
+  static Future<String?> readLastUrl() async {
+    return _storage.read(key: _kBase);
+  }
 }