feat(plugin-basic-ui): export css variables from components (#432)

Author: orionmiz

.changeset/mean-zebras-accept.md

@@ -0,0 +1,5 @@
+---
+"@stackflow/plugin-basic-ui": minor
+---
+
+feat(plugin-basic-ui): export css variables from components

extensions/plugin-basic-ui/src/index.ts

@@ -7,8 +7,11 @@ export {
   AppScreenProps,
   useAppScreen,
 } from "./components/AppScreen";
+export { vars as appScreenVars } from "./components/AppScreen.css";
 export {
   default as BottomSheet,
   BottomSheetProps,
 } from "./components/BottomSheet";
+export { vars as bottomSheetVars } from "./components/BottomSheet.css";
 export { default as Modal, ModalProps } from "./components/Modal";
+export { vars as modalVars } from "./components/Modal.css";