Fix Compose Multiplatform JavaScript build

[Copilot]

Description

Add an executable JavaScript binary to the library convention so Compose UI tests can be bundled correctly with webpack after upgrading the Compose Multiplatform plugin.

Related Issue

Fixes #

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Code refactoring
• Performance improvement
• Build/CI improvement

Changes Made

• Configure binaries.executable() for the library JavaScript target.
• Resolve the checkComposeUiTestConfigurationForJs build failure.

Platforms Tested

• Android
• iOS
• Desktop (JVM)
• JavaScript
• WebAssembly

Screenshots / Videos

Not applicable.

Testing

Manual Testing

• Tested on physical device/emulator
• Tested different screen sizes
• Tested light and dark themes (if applicable)
• Tested enabled/disabled states (if applicable)

Automated Testing

• Added/updated unit tests
• Added/updated integration tests
• All existing tests pass locally; local validation was blocked by Dokka 2.2.0 plugin resolution.

Checklist

• My code follows the project's code style guidelines
• I have performed a self-review of my code
• I have commented my code where necessary, particularly in complex areas
• I have updated the documentation (README, KDoc, etc.) if needed
• My changes generate no new warnings or errors
• I have added tests that prove my fix is effective or that my feature works
• New and existing tests pass locally with my changes
• I have checked that my changes work across all relevant platforms
• I have updated CLAUDE.md if architectural changes were made

Breaking Changes

Not applicable.

Additional Notes

The CI failure reported that the JS target had no executable binary, preventing Compose UI tests from being bundled with webpack.