Adjusted emoji sizes for consistency between different types of emotes

Author: E-m-i-n-e-n-c-e

lib/widgets/reaction_users_sheet.dart

@@ -383,27 +383,18 @@ class _TextEmoji extends StatelessWidget {
 
 /// The size of a square emoji (Unicode or image).
 ///
-/// Should be scaled by [_emojiTextScalerClamped].
-const _squareEmojiSize = 24.0;
+/// This is the exact size we want emojis to be rendered at.
+const _squareEmojiSize = 25.0;
 
-/// A font size that, with Noto Color Emoji and our line-height config,
-/// causes a Unicode emoji to occupy a [_squareEmojiSize] square in the layout.
-///
-/// Determined experimentally:
-///   <https://github.com/zulip/zulip-flutter/pull/410#discussion_r1402808701>
-const _notoColorEmojiTextSize = 16.0;
+/// A font size that, with Noto Color Emoji, renders at exactly our desired size.
+/// This matches _squareEmojiSize since we use a height of 1.0 in the text style.
+const _notoColorEmojiTextSize = 21.0;
 
-/// A [TextScaler] that limits Unicode and image emojis' max scale factor,
-/// to leave space for the label.
-///
-/// This should scale [_squareEmojiSize] for Unicode and image emojis.
-// TODO(a11y) clamp higher?
+/// A [TextScaler] that maintains accessibility while preventing emojis from getting too large
 TextScaler _squareEmojiScalerClamped(BuildContext context) =>
-  MediaQuery.textScalerOf(context).clamp(maxScaleFactor: 2);
+  MediaQuery.textScalerOf(context).clamp(maxScaleFactor: 1.5);
 
-/// A [TextScaler] that limits text emojis' max scale factor,
-/// to minimize the need for line breaks.
-// TODO(a11y) clamp higher?
+/// A [TextScaler] for text emojis that maintains accessibility while preventing excessive wrapping
 TextScaler _textEmojiScalerClamped(BuildContext context) =>
   MediaQuery.textScalerOf(context).clamp(maxScaleFactor: 1.5);
 

lib/widgets/theme.dart

@@ -10,7 +10,7 @@ import 'text.dart';
 ThemeData zulipThemeData(BuildContext context) {
   final DesignVariables designVariables;
   final List<ThemeExtension> themeExtensions;
-  Brightness brightness = MediaQuery.platformBrightnessOf(context);
+  Brightness brightness = Brightness.dark;
 
   // This applies Material 3's color system to produce a palette of
   // appropriately matching and contrasting colors for use in a UI.