feat: update privacy policy and add version code (#4343)

Author: LucasXu0

frontend/appflowy_flutter/lib/mobile/presentation/setting/about/about.dart

@@ -1,3 +1,2 @@
 export 'about_setting_group.dart';
-export 'privacy_policy_page.dart';
 export 'user_agreement_page.dart';

frontend/appflowy_flutter/lib/mobile/presentation/setting/about/about_setting_group.dart

@@ -1,10 +1,11 @@
 import 'package:appflowy/generated/locale_keys.g.dart';
+import 'package:appflowy/startup/tasks/device_info_task.dart';
+import 'package:appflowy_editor/appflowy_editor.dart';
 import 'package:easy_localization/easy_localization.dart';
+import 'package:flowy_infra_ui/flowy_infra_ui.dart';
 import 'package:flutter/material.dart';
-import 'package:go_router/go_router.dart';
 
 import '../widgets/widgets.dart';
-import 'about.dart';
 
 class AboutSettingGroup extends StatelessWidget {
   const AboutSettingGroup({
@@ -21,18 +22,21 @@ class AboutSettingGroup extends StatelessWidget {
           trailing: const Icon(
             Icons.chevron_right,
           ),
-          onTap: () {
-            context.push(PrivacyPolicyPage.routeName);
-          },
+          onTap: () => safeLaunchUrl('https://appflowy.io/privacy/mobile'),
         ),
         MobileSettingItem(
-          name: LocaleKeys.settings_mobile_userAgreement.tr(),
+          name: LocaleKeys.settings_mobile_termsAndConditions.tr(),
           trailing: const Icon(
             Icons.chevron_right,
           ),
-          onTap: () {
-            context.push(UserAgreementPage.routeName);
-          },
+          onTap: () => safeLaunchUrl('https://appflowy.io/terms'),
+        ),
+        MobileSettingItem(
+          name: LocaleKeys.settings_mobile_version.tr(),
+          trailing: FlowyText(
+            '${DeviceOrApplicationInfoTask.applicationVersion} (${DeviceOrApplicationInfoTask.buildNumber})',
+            color: Theme.of(context).colorScheme.onSurface,
+          ),
         ),
       ],
       showDivider: false,

frontend/appflowy_flutter/lib/mobile/presentation/setting/about/privacy_policy_page.dart

@@ -34,7 +34,7 @@ class KeyboardHeightObserver {
 
   void notify(double height) {
     // the keyboard height will notify twice with the same value on Android 14
-    if (DeviceInfoTask.androidSDKVersion == 34) {
+    if (DeviceOrApplicationInfoTask.androidSDKVersion == 34) {
       if (height == 0 && currentKeyboardHeight == 0) {
         return;
       }

frontend/appflowy_flutter/lib/plugins/document/presentation/editor_plugins/mobile_toolbar_v3/keyboard_height_observer.dart

@@ -109,7 +109,7 @@ class FlowyRunner {
         // there's a flag named _enable in memory_leak_detector.dart. If it's false, the task will be ignored.
         MemoryLeakDetectorTask(),
         const DebugTask(),
-        const DeviceInfoTask(),
+        const DeviceOrApplicationInfoTask(),
         // localization
         const InitLocalizationTask(),
         // init the app window

frontend/appflowy_flutter/lib/startup/startup.dart

@@ -1,21 +1,31 @@
 import 'dart:io';
 
 import 'package:device_info_plus/device_info_plus.dart';
+import 'package:package_info_plus/package_info_plus.dart';
 
 import '../startup.dart';
 
-class DeviceInfoTask extends LaunchTask {
-  const DeviceInfoTask();
+class DeviceOrApplicationInfoTask extends LaunchTask {
+  const DeviceOrApplicationInfoTask();
 
   static int androidSDKVersion = -1;
+  static String applicationVersion = '';
+  static String buildNumber = '';
 
   @override
   Future<void> initialize(LaunchContext context) async {
     final DeviceInfoPlugin deviceInfoPlugin = DeviceInfoPlugin();
+    final PackageInfo packageInfo = await PackageInfo.fromPlatform();
+
     if (Platform.isAndroid) {
       final androidInfo = await deviceInfoPlugin.androidInfo;
       androidSDKVersion = androidInfo.version.sdkInt;
     }
+
+    if (Platform.isAndroid || Platform.isIOS) {
+      applicationVersion = packageInfo.version;
+      buildNumber = packageInfo.buildNumber;
+    }
   }
 
   @override

frontend/appflowy_flutter/lib/startup/tasks/device_info_task.dart

@@ -47,7 +47,6 @@ GoRouter generateRouter(Widget child) {
       if (PlatformExtension.isMobile) ...[
         // settings
         _mobileHomeSettingPageRoute(),
-        _mobileSettingPrivacyPolicyPageRoute(),
         _mobileSettingUserAgreementPageRoute(),
         _mobileCloudSettingAppFlowyCloudPageRoute(),
 
@@ -196,16 +195,6 @@ GoRoute _mobileHomeSettingPageRoute() {
   );
 }
 
-GoRoute _mobileSettingPrivacyPolicyPageRoute() {
-  return GoRoute(
-    parentNavigatorKey: AppGlobals.rootNavKey,
-    path: PrivacyPolicyPage.routeName,
-    pageBuilder: (context, state) {
-      return const MaterialPage(child: PrivacyPolicyPage());
-    },
-  );
-}
-
 GoRoute _mobileCloudSettingAppFlowyCloudPageRoute() {
   return GoRoute(
     parentNavigatorKey: AppGlobals.rootNavKey,

frontend/appflowy_flutter/lib/startup/tasks/generate_router.dart

@@ -447,10 +447,12 @@
       "joinDiscord": "Join us in Discord",
       "privacyPolicy": "Privacy Policy",
       "userAgreement": "User Agreement",
+      "termsAndConditions": "Terms and Conditions",
       "userprofileError": "Failed to load user profile",
       "userprofileErrorDescription": "Please try to log out and log back in to check if the issue still persists.",
       "selectLayout": "Select layout",
-      "selectStartingDay": "Select starting day"
+      "selectStartingDay": "Select starting day",
+      "version": "Version"
     }
   },
   "grid": {