Clear and concise description of the problem

stretch size cannot be specified with UnoCSS, despite being available since Chromium 138 and as -webkit-fill-available since much longer, including in Safari and Firefox.

Suggested solution

Suggested addition:
w-stretch -> width: -webkit-fill-available; width: stretch
Likewise for height.

Alternative

Users define their own rules

Additional context

https://caniuse.com/?search=webkit-fill-available

Validations

• Read the Contributing Guidelines.
• Read the README.md of using the package.
• Already used the Interactive Docs.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.