Refactor theme system and remove unused platforms

- Overhaul theme system with Svrnty design and WCAG AAA compliance
- Remove android, macos, and web platform files (iOS-only focus)
- Update components with improved dark mode map and UI refinements
- Enhance settings page with additional configuration options
- Add theme system documentation in lib/theme/README.md
- Update CLAUDE.md with comprehensive theme guidelines

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

lib/utils/toast_helper.dart

@@ -48,14 +48,18 @@ class ToastHelper {
     final screenWidth = MediaQuery.of(context).size.width;
     final screenHeight = MediaQuery.of(context).size.height;
     final topPadding = MediaQuery.of(context).padding.top;
+    final bottomPadding = MediaQuery.of(context).padding.bottom;
     final toastWidth = screenWidth * 0.5; // 50% of screen width
     final horizontalMargin = (screenWidth - toastWidth) / 2;
 
-    // Position toast very close to top (10px into safe area)
-    final topMargin = topPadding - 10;
+    // Position toast at top with safe padding
+    final topMargin = topPadding + 10;
     const toastHeight = 60.0;
     final bottomMargin = screenHeight - topMargin - toastHeight;
 
+    // Ensure bottom margin is at least the safe area padding
+    final safeBottomMargin = bottomMargin > bottomPadding ? bottomMargin : bottomPadding + 10;
+
     ScaffoldMessenger.of(context).showSnackBar(
       SnackBar(
         content: Text(
@@ -72,7 +76,7 @@ class ToastHelper {
           top: topMargin,
           left: horizontalMargin,
           right: horizontalMargin,
-          bottom: bottomMargin,
+          bottom: safeBottomMargin,
         ),
       ),
     );