fix: pincode functionality

lib/views/settings_view.dart

@@ -1,3 +1,5 @@
+import 'dart:io';
+
 import 'package:flutter/material.dart';
 import 'package:go_router/go_router.dart';
 import 'package:package_info_plus/package_info_plus.dart';
@@ -55,32 +57,37 @@ class _SettingsScreenViewState extends State<SettingsScreenView> {
     });
   }
 
-  Future<String?> _promptPin(String title, {String hint = 'Enter PIN'}) {
+  Future<String?> _promptPin(String title, {String hint = 'Enter PIN (4 digits)'}) {
     final controller = TextEditingController();
 
     return showDialog<String>(
       context: context,
       builder: (context) => AlertDialog(
         title: Text(title),
-        content: TextField(
-          controller: controller,
-          autofocus: true,
-          obscureText: true,
-          keyboardType: TextInputType.number,
-          maxLength: 6,
-          decoration: InputDecoration(hintText: hint),
+        contentPadding: const EdgeInsets.fromLTRB(24, 20, 24, 0),
+        content: SizedBox(
+          width: 320,
+          child: TextField(
+            controller: controller,
+            autofocus: true,
+            obscureText: true,
+            keyboardType: TextInputType.number,
+            maxLength: 4,
+            decoration: InputDecoration(hintText: hint),
+          ),
         ),
+        actionsPadding: const EdgeInsets.fromLTRB(16, 8, 16, 12),
         actions: [
           TextButton(
             onPressed: () => Navigator.pop(context),
             child: const Text('Cancel'),
           ),
+          const SizedBox(width: 12),
           FilledButton(
             onPressed: () => Navigator.pop(context, controller.text),
             child: const Text('Confirm'),
           ),
         ],
-        actionsPadding: const EdgeInsets.symmetric(horizontal: 8),
       ),
     );
   }
@@ -93,11 +100,11 @@ class _SettingsScreenViewState extends State<SettingsScreenView> {
   }
 
   Future<void> _enablePin() async {
-    final pin = await _promptPin('Set PIN Code', hint: '4–6 digits');
+    final pin = await _promptPin('Set PIN Code', hint: '4 digits');
     if (pin == null) return;
 
-    if (pin.length < 4) {
-      _showError('PIN must be at least 4 digits');
+    if (pin.length != 4) {
+      _showError('PIN must be exactly 4 digits');
       return;
     }
 
@@ -109,6 +116,7 @@ class _SettingsScreenViewState extends State<SettingsScreenView> {
       return;
     }
 
+    pinLockViewModel.setPinRequired(true);
     await context.read<SettingsViewModel>().updatePinRequired(true);
   }
 
@@ -116,11 +124,11 @@ class _SettingsScreenViewState extends State<SettingsScreenView> {
     final current = await _promptPin('Enter Current PIN');
     if (current == null) return;
 
-    final newPin = await _promptPin('Enter New PIN', hint: '4–6 digits');
+    final newPin = await _promptPin('Enter New PIN', hint: '4 digits');
     if (newPin == null) return;
 
-    if (newPin.length < 4) {
-      _showError('PIN must be at least 4 digits');
+    if (newPin.length != 4) {
+      _showError('PIN must be exactly 4 digits');
       return;
     }
 
@@ -147,6 +155,7 @@ class _SettingsScreenViewState extends State<SettingsScreenView> {
       return;
     }
 
+    pinLockViewModel.setPinRequired(false);
     await context.read<SettingsViewModel>().updatePinRequired(false);
   }
 
@@ -252,20 +261,21 @@ class _SettingsScreenViewState extends State<SettingsScreenView> {
                   ),
                 ],
               ),
-              _SettingsSection(
-                title: 'Updates',
-                children: [
-                  _SettingsTile(
-                    icon: Icons.system_update_alt_rounded,
-                    title: settingsViewModel.checkingForUpdates
-                        ? 'Checking for updates...'
-                        : 'Check for updates',
-                    onTap: settingsViewModel.checkingForUpdates
-                        ? null
-                        : _checkForUpdates,
-                  ),
-                ],
-              ),
+              if (Platform.isAndroid)
+                _SettingsSection(
+                  title: 'Updates',
+                  children: [
+                    _SettingsTile(
+                      icon: Icons.system_update_alt_rounded,
+                      title: settingsViewModel.checkingForUpdates
+                          ? 'Checking for updates...'
+                          : 'Check for updates',
+                      onTap: settingsViewModel.checkingForUpdates
+                          ? null
+                          : _checkForUpdates,
+                    ),
+                  ],
+                ),
               const SizedBox(height: 40),
               GestureDetector(
                 onTap: _onVersionTap,
@@ -289,6 +299,7 @@ class _SettingsScreenViewState extends State<SettingsScreenView> {
   }
 
   Future<void> _checkForUpdates() async {
+    if (!Platform.isAndroid) return;
     final vm = context.read<SettingsViewModel>();
 
     try {