Move /platform/detection vars into /env (#9707)

* Add platform vars to env

* Replace /platform/detection with /env

src/screens/Messages/Conversation.tsx

@@ -21,7 +21,6 @@ import {
   type CommonNavigatorParams,
   type NavigationProp,
 } from '#/lib/routes/types'
-import {isWeb} from '#/platform/detection'
 import {type Shadow, useMaybeProfileShadow} from '#/state/cache/profile-shadow'
 import {useEmail} from '#/state/email-verification'
 import {ConvoProvider, isConvoActive, useConvo} from '#/state/messages/convo'
@@ -43,6 +42,7 @@ import {MessagesListHeader} from '#/components/dms/MessagesListHeader'
 import {Error} from '#/components/Error'
 import * as Layout from '#/components/Layout'
 import {Loader} from '#/components/Loader'
+import {IS_WEB} from '#/env'
 
 type Props = NativeStackScreenProps<
   CommonNavigatorParams,
@@ -74,7 +74,7 @@ export function MessagesConversationScreenInner({route}: Props) {
     useCallback(() => {
       setCurrentConvoId(convoId)
 
-      if (isWeb && !gtMobile) {
+      if (IS_WEB && !gtMobile) {
         setMinimalShellMode(true)
       } else {
         setMinimalShellMode(false)