Fluent: QoL improvements

[OEvgeny]

Changelog Entry

Fixed

• Resolved CSS class name conflicts between component and fluent packages to prevent styling issues, in PR #5326, in PR #5327, by @OEvgeny

Description

This PR improves the test environment and implements a better short-term fix for CSS classes clashing.

Specific Changes

• Updated BorderFlair.module.css, BorderLoader.module.css, and ActivityDecorator.module.css:
  • Reverted to single-class selectors previous fix.
• Modified Theme.module.css in the fluent-theme package:
  • Added a list of single-letter classes in the global scope to prevent usage by esbuild.
• Updated tsup.base.config.ts:
  • Enabled minification for the test environment to better simulate production conditions.
• Modified docker-compose-wsl2.yml:
  • Exposed port 5081 to improve local testing.

-

• I have added tests and executed them locally
• I have updated CHANGELOG.md
• I have updated documentation

Review Checklist

• Accessibility reviewed (tab order, content readability, alt text, color contrast)
• Browser and platform compatibilities reviewed
• CSS styles reviewed (minimal rules, no z-index)
• Documents reviewed (docs, samples, live demo)
• Internationalization reviewed (strings, unit formatting)
• package.json and package-lock.json reviewed
• Security reviewed (no data URIs, check for nonce leak)
• Tests reviewed (coverage, legitimacy)