mobile: improve usability for exiting stream

js/mobile/src/features/stream-view/StreamView.tsx

@@ -3,6 +3,7 @@ import { Alert, Dimensions, Pressable, Text, View } from "react-native";
 import { SafeAreaView, useSafeAreaInsets } from "react-native-safe-area-context";
 import { StatusBar } from "expo-status-bar";
 import * as Haptics from "expo-haptics";
+import { ChevronDown } from "lucide-react-native";
 import {
   Gesture,
   GestureDetector,
@@ -538,9 +539,17 @@ function StreamViewInner({ streamParticle, path, onExit }: StreamViewProps) {
         >
           <View className="px-4" pointerEvents="box-none">
             <View
-              className="flex-row items-start gap-3"
+              className="flex-row items-start gap-2"
               pointerEvents="box-none"
             >
+              <Pressable
+                onPress={exit}
+                accessibilityLabel="Close stream"
+                hitSlop={8}
+                className="bg-white/10 active:bg-white/20 h-8 w-8 items-center justify-center rounded-full"
+              >
+                <ChevronDown color="white" size={18} strokeWidth={2} />
+              </Pressable>
               <View className="flex-1" pointerEvents="none">
                 <StreamMetadataHeader
                   particle={currentParticle}