fix(store): render feature-graphic wordmark with real font (Titan One, OFL)

The flutter_test default font draws every glyph as a box, so the wordmark was
unreadable. Load the OFL Titan One TTF via FontLoader in the generator and
render 'Block Seasons' + tagline with it; fit the text within the 1024 width.
Font used only by the asset generator, not bundled in the app.

test/tool/generate_brand_assets_test.dart

@@ -4,6 +4,7 @@ import 'dart:ui';
 
 import 'package:block_seasons/ui/branding/app_icon_painter.dart';
 import 'package:block_seasons/ui/branding/feature_graphic_painter.dart';
+import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 Future<void> _writePng(String path, int size, void Function(Canvas) draw) async {
@@ -45,6 +46,14 @@ void main() {
 
   testWidgets('generate feature graphic', (tester) async {
     await tester.runAsync(() async {
+      // Load the real display font (OFL Titan One) so the wordmark renders as
+      // glyphs — the flutter_test default font draws every char as a box.
+      final fontBytes =
+          File('tool/fonts/TitanOne-Regular.ttf').readAsBytesSync();
+      final loader = FontLoader('TitanOne')
+        ..addFont(Future.value(ByteData.view(fontBytes.buffer)));
+      await loader.load();
+
       const w = 1024, h = 500;
       final recorder = PictureRecorder();
       final canvas = Canvas(recorder);