[FEATURE] dart, dart test, dart run build_runner in CLaude Code Web

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

• specific needs: dart, dart test, dart run build_runner
• Use case (TDD workflow with dart_mappable)

Mention the impact:

• Cannot run tests (dart test)
• Cannot generate code (dart run build_runner build)
• Limits TDD workflow effectiveness in web environment
• Forces users to pull changes locally to verify

Workaround for now: Since Dart isn't available in the web sandbox, the current workflow is:

1. Claude Code Web -> create/modify code and commit to git
2. You pull changes locally
3. You run dart pub get, dart run build_runner build, and dart test
4. You provide feedback if there are issues

Proposed Solution

Add dart support which could then implicitly provide dart test, dart run build_runner

Alternative Solutions

_No response_

Priority

High - Significant impact on productivity

Feature Category

Interactive mode (TUI)

Use Case Example

Using Dart.
Using TDD in Dart.
Using packages that need to run build_runner

Additional Context

_No response_