Keep screen awake in camera mode; nudge flip button toward shutter

src/components/CameraControls.tsx

@@ -32,7 +32,7 @@ export default function CameraControls({
       className="flex-row items-center justify-between px-7 pt-2"
     >
       {/* Left cluster: Pick Image + gear (gear sits between library & shutter) */}
-      <View className="flex-row items-center space-x-3">
+      <View className="flex-row items-center gap-x-3">
         <TouchableOpacity
           onPress={onPickImage}
           className="w-12 h-12 rounded-full bg-black/40 border border-zinc-700/70 flex items-center justify-center"
@@ -73,8 +73,9 @@ export default function CameraControls({
 
       {/* Right cluster: flip camera (between shutter & preview) + preview.
           Preview doubles as "back to camera" while in library mode; the flip
-          control is hidden then. */}
-      <View className="flex-row items-center space-x-3">
+          control is hidden then. Wider gap than the left cluster keeps the flip
+          button clear of the preview thumbnail (~2 glyph widths toward shutter). */}
+      <View className="flex-row items-center gap-x-8">
         {!isLibraryMode && onFlipCamera && (
           <TouchableOpacity
             onPress={onFlipCamera}

src/components/Viewfinder.tsx

@@ -1,6 +1,7 @@
 import React, { useCallback, useEffect, useMemo, useRef, useState, forwardRef, useImperativeHandle, type ComponentProps } from 'react';
 import { View, Text, StyleSheet, TouchableOpacity, useWindowDimensions, AppState } from 'react-native';
 import { useSafeAreaInsets } from 'react-native-safe-area-context';
+import { activateKeepAwake, deactivateKeepAwake } from 'expo-keep-awake';
 import { useCameraDevice, type CameraPhotoOutput } from 'react-native-vision-camera';
 import { SkiaCamera, type SkiaCameraRef } from 'react-native-vision-camera-skia';
 import { createSynchronizable } from 'react-native-worklets';
@@ -313,6 +314,17 @@ const Viewfinder = forwardRef<ViewfinderHandle, ViewfinderProps>(function Viewfi
     const sub = AppState.addEventListener('change', (s) => setAppActive(s === 'active'));
     return () => sub.remove();
   }, []);
+  // Keep the screen lit while the live camera is showing. Without this the
+  // display sleeps after the system timeout; when the user wakes it much later
+  // (deep idle/doze) the preview surface is gone but the JS AppState never saw
+  // a background event, so the session is never restarted and the viewfinder
+  // (and capture) stay black until the camera is re-mounted (flip/switch).
+  useEffect(() => {
+    if (mode === 'camera') {
+      activateKeepAwake('camera-viewfinder');
+      return () => deactivateKeepAwake('camera-viewfinder');
+    }
+  }, [mode]);
   // Tap-to-focus / AE-AF-AWB lock point (view coords). null = auto continuous.
   const [focusPoint, setFocusPoint] = useState<{ x: number; y: number } | null>(null);
   const controller = cameraActive ? skiaCameraRef.current?.controller : undefined;