refactor: Switch to ubuntu font

lib/config/themes.dart

@@ -1,7 +1,6 @@
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 
-import 'package:fluffychat/utils/platform_infos.dart';
 import 'app_config.dart';
 
 abstract class FluffyThemes {
@@ -19,7 +18,7 @@ abstract class FluffyThemes {
       MediaQuery.of(context).size.width > FluffyThemes.columnWidth * 3.5;
 
   static const fallbackTextStyle = TextStyle(
-    fontFamily: 'Roboto',
+    fontFamily: 'Ubuntu',
     fontFamilyFallback: ['NotoEmoji'],
   );
 
@@ -73,11 +72,7 @@ abstract class FluffyThemes {
       useMaterial3: true,
       brightness: brightness,
       colorScheme: colorScheme,
-      textTheme: PlatformInfos.isDesktop
-          ? brightness == Brightness.light
-              ? Typography.material2018().black.merge(fallbackTextTheme)
-              : Typography.material2018().white.merge(fallbackTextTheme)
-          : null,
+      textTheme: fallbackTextTheme,
       dividerColor: colorScheme.surfaceContainer,
       popupMenuTheme: PopupMenuThemeData(
         shape: RoundedRectangleBorder(

lib/pages/bootstrap/bootstrap_dialog.dart

@@ -132,7 +132,7 @@ class BootstrapDialogState extends State<BootstrapDialog> {
                   minLines: 2,
                   maxLines: 4,
                   readOnly: true,
-                  style: const TextStyle(fontFamily: 'RobotoMono'),
+                  style: const TextStyle(fontFamily: 'UbuntuMono'),
                   controller: TextEditingController(text: key),
                   decoration: const InputDecoration(
                     contentPadding: EdgeInsets.all(16),
@@ -257,7 +257,7 @@ class BootstrapDialogState extends State<BootstrapDialog> {
                           ? null
                           : [AutofillHints.password],
                       controller: _recoveryKeyTextEditingController,
-                      style: const TextStyle(fontFamily: 'RobotoMono'),
+                      style: const TextStyle(fontFamily: 'UbuntuMono'),
                       decoration: InputDecoration(
                         contentPadding: const EdgeInsets.all(16),
                         hintStyle: TextStyle(

lib/pages/chat_encryption_settings/chat_encryption_settings_view.dart

@@ -169,7 +169,7 @@ class ChatEncryptionSettingsView extends StatelessWidget {
                             deviceKeys[i].ed25519Key?.beautified ??
                                 L10n.of(context).unknownEncryptionAlgorithm,
                             style: TextStyle(
-                              fontFamily: 'RobotoMono',
+                              fontFamily: 'UbuntuMono',
                               color: theme.colorScheme.secondary,
                             ),
                           ),