Theme Lens - a Flutter theme checked for Material 3, then migrated

Check a Flutter theme against Material 3, then migrate it. Free in your browser: the pasted Dart scanned for useMaterial3: false and primarySwatch, the deprecated accentColor, accentColorBrightness, accentIconTheme and accentTextTheme, AppBarTheme color, *Theme classes where ThemeData takes the *ThemeData classes, the removed FlatButton, RaisedButton and OutlineButton, Material 2 navigation components, ColorScheme role pairs under 4.5:1 with a measured passing colour, widgets that hard-code colours and font sizes, a missing or differently seeded dark theme and desktop idioms - plus the skill's migration checklist, a findings CSV and a starter theme from your seed. Metered runs write the review (each finding confirmed or cleared, what a scan cannot see, the migration in order) and the whole migrated file, which the page re-scans. Built on the SkillSafe skill @flutter/flutter-theming-apps, from flutter/skills (BSD-3-Clause), by the Flutter team.