dart

# Dart coding conventions - Prefer `final` over `var` where the value never changes. - Use lowerCamelCase for variables and functions, UpperCamelCase for types. - Keep functions small and focused; prefer pure functions where practical. - Always handle errors explicitly; avoid swallowing exceptions silently. - Add a doc comment (`///`) to every public declaration. - Use `dart format` defaults (80-column width) for all files. - Prefer collection literals and spread operators over imperative building.