Polish navigation, Quran flows, and sharing UX

lib/app/theme/app_text_styles.dart

@@ -1,11 +1,22 @@
 import 'package:flutter/material.dart';
 
 /// Typography definitions from PRD §3.2.
-/// Plus Jakarta Sans (bundled) for UI text, Amiri (bundled) for Arabic content.
+/// Plus Jakarta Sans (bundled) for UI text.
+/// Scheherazade New (bundled) for Arabic/Quran text, with Uthman/KFGQPC fallback.
 class AppTextStyles {
   AppTextStyles._();
 
   static const String _fontFamily = 'PlusJakartaSans';
+  static const String _arabicFontFamily = 'ScheherazadeNew';
+  static const List<String> _arabicFallbackFamilies = <String>[
+    'UthmanTahaNaskh',
+    'KFGQPCUthmanicHafs',
+    'Amiri',
+    'Noto Naskh Arabic',
+    'Noto Sans Arabic',
+    'Droid Arabic Naskh',
+    'sans-serif',
+  ];
 
   /// Builds the full TextTheme for the app using bundled Plus Jakarta Sans.
   static const TextTheme textTheme = TextTheme(
@@ -52,19 +63,21 @@ class AppTextStyles {
     ),
   );
 
-  // ── Arabic text styles (Amiri — bundled font) ──
+  // ── Arabic text styles (Scheherazade New — bundled font) ──
 
   static const TextStyle arabicBody = TextStyle(
-    fontFamily: 'Amiri',
+    fontFamily: _arabicFontFamily,
+    fontFamilyFallback: _arabicFallbackFamilies,
     fontSize: 24,
     fontWeight: FontWeight.w400,
-    height: 2.0,
+    height: 1.8,
   );
 
   static const TextStyle arabicLarge = TextStyle(
-    fontFamily: 'Amiri',
+    fontFamily: _arabicFontFamily,
+    fontFamilyFallback: _arabicFallbackFamilies,
     fontSize: 28,
     fontWeight: FontWeight.w400,
-    height: 2.2,
+    height: 2.0,
   );
 }