v0.2.0 of cartographer

Auto-discover and visualize a Flutter app's navigation graph as an interactive sitemap. Dev-only. Changelog excerpt: ### Changed - README rewritten for the published package: leads with dart pub global activate cartographer(the right install model for a CLI tool, and the only one that works around the analyzer 13 / Flutter SDK metapin), surfaces the pub.dev page link, and documents the viewer's full feature set (2D/3D, themes, depth heatmap, upload + drag-drop). ### Fixed - CI lint job now installs the Flutter SDK so dart pub getresolves the nested example/pubspec (Dart 3.11+ auto-discovers nested p[...]