[Clipclops] New routes with placeholder screens (#3725)

* add new routes with placeholder screens

* gate content

* add filled envelope style

* swap filled state

* switch to `useAgent`

src/screens/Messages/Conversation/index.tsx

@@ -0,0 +1,32 @@
+import React from 'react'
+import {View} from 'react-native'
+import {msg} from '@lingui/macro'
+import {useLingui} from '@lingui/react'
+import {NativeStackScreenProps} from '@react-navigation/native-stack'
+
+import {CommonNavigatorParams} from '#/lib/routes/types'
+import {useGate} from '#/lib/statsig/statsig'
+import {ViewHeader} from '#/view/com/util/ViewHeader'
+import {ClipClopGate} from '../gate'
+
+type Props = NativeStackScreenProps<
+  CommonNavigatorParams,
+  'MessagesConversation'
+>
+export function MessagesConversationScreen({route}: Props) {
+  const chatId = route.params.conversation
+  const {_} = useLingui()
+
+  const gate = useGate()
+  if (!gate('dms')) return <ClipClopGate />
+
+  return (
+    <View>
+      <ViewHeader
+        title={_(msg`Chat with ${chatId}`)}
+        showOnDesktop
+        showBorder
+      />
+    </View>
+  )
+}