Windows compatibility parity tracker

[tsavo-at-pieces]

Goal

Achieve total and complete compatibility for cli_script on Windows (windows-x64 + windows-arm64) while keeping Linux/macOS behavior stable.

Failing reference run

• CI run: https://github.com/open-runtime/dart_cli_script/actions/runs/22376939954
• windows-x64 job: https://github.com/open-runtime/dart_cli_script/actions/runs/22376939954/job/64769258023
• windows-arm64 job: https://github.com/open-runtime/dart_cli_script/actions/runs/22376939954/job/64769258042

Current failure clusters (10 tests per Windows runner)

• Absolute glob expansion (ls_test.dart, cli_arguments_test.dart)
• Subprocess environment propagation and includeParentEnvironment: false behavior (sub_process_test.dart)
• Locale-sensitive ProcessException stderr assertion (sub_process_test.dart)
• LF vs CRLF bytes expectation in outputBytes test (sub_process_test.dart)

Linked implementation issues

• Absolute glob expansion on Windows
• Subprocess environment behavior on Windows
• Windows-specific stderr/line-ending test robustness

Compatibility standard (acceptance)

• CI passes on windows-x64 and windows-arm64
• No Windows-only failing tests in ls_test.dart, cli_arguments_test.dart, sub_process_test.dart
• Platform-specific behavior is explicitly documented where expected (signals, line endings, environment casing)
• No regressions on Linux/macOS

Notes

This is the parent tracking issue for completion and release readiness.

[tsavo-at-pieces]

Linked child issues for execution:\n- #2 Windows: absolute glob expansion fails in ls() and CliArguments\n- #3 Windows: subprocess environment propagation breaks with includeParentEnvironment=false\n- #4 Windows: make stderr and outputBytes assertions robust to locale and CRLF