[FIX] 검사 중 뒤로가기 및 하단 탭 이동 방지

app/(tabs)/(home)/scanning.tsx

@@ -2,12 +2,13 @@ import { useAuth } from '@clerk/expo';
 import LottieView from 'lottie-react-native';
 import { router, Stack, useLocalSearchParams } from 'expo-router';
 import { useEffect, useRef, useState } from 'react';
-import { StyleSheet, Text, TouchableOpacity, useWindowDimensions, View } from 'react-native';
+import { BackHandler, StyleSheet, Text, TouchableOpacity, useWindowDimensions, View } from 'react-native';
 import { useBottomTabBarHeight } from '@react-navigation/bottom-tabs';
 
 import { fetchAnalysis, requestAnalysis, type AnalysisResponse, type AnalysisVerdict } from '@/api/analyses';
 import { ApiError } from '@/api/api-client';
 import { Colors, Typography } from '@/constants/theme';
+import { AppIcon } from '@/components/ui/app-icon';
 import { useGuardedPress } from '@/utils/press-guard';
 
 const POLLING_INTERVAL_MS = 2_000;
@@ -104,9 +105,22 @@ export default function ScanningScreen() {
   }, [isLoaded, isSignedIn, retryKey, url]);
 
   const hasError = errorMessage.length > 0;
+  const isScanning = !hasError;
   const guardedRetry = useGuardedPress(() => setRetryKey((key) => key + 1));
   const guardedBack = useGuardedPress(() => router.back());
 
+  useEffect(() => {
+    if (!isScanning) {
+      return undefined;
+    }
+
+    const subscription = BackHandler.addEventListener('hardwareBackPress', () => true);
+
+    return () => {
+      subscription.remove();
+    };
+  }, [isScanning]);
+
   return (
     <>
       <Stack.Screen
@@ -118,6 +132,17 @@ export default function ScanningScreen() {
           headerTitleStyle: { ...Typography.title, color: Colors.brand.text },
           headerTintColor: Colors.brand.text,
           headerShadowVisible: false,
+          headerBackVisible: !isScanning,
+          gestureEnabled: !isScanning,
+          headerLeft: isScanning
+            ? () => (
+                <AppIcon
+                  name="back"
+                  disabled
+                  style={styles.headerBackButton}
+                />
+              )
+            : undefined,
         }}
       />
       <View
@@ -330,6 +355,10 @@ const styles = StyleSheet.create({
     paddingHorizontal: 24,
     paddingTop: 40,
   },
+  headerBackButton: {
+    width: 44,
+    height: 44,
+  },
   containerCompact: {
     paddingTop: 20,
   },

app/(tabs)/_layout.tsx

@@ -20,12 +20,36 @@ const TAB_TO_HREF: Partial<Record<TabVariant, string>> = {
   folder: '/(tabs)/(folder)',
 };
 
+type NestedRoute = {
+  name?: string;
+  state?: {
+    index?: number;
+    routes?: NestedRoute[];
+  };
+};
+
+function getActiveNestedRouteName(route?: NestedRoute): string | undefined {
+  const nestedState = route?.state;
+
+  if (!nestedState?.routes?.length) {
+    return route?.name;
+  }
+
+  const nestedIndex = nestedState.index ?? 0;
+  return getActiveNestedRouteName(nestedState.routes[nestedIndex]);
+}
+
 function CustomTabBar({ state }: BottomTabBarProps) {
   const activeRoute = state.routes[state.index];
   const activeRouteName = activeRoute?.name ?? '(home)';
   const activeTab = ROUTE_TO_TAB[activeRouteName] ?? 'home';
+  const isScanningRoute = getActiveNestedRouteName(activeRoute as NestedRoute) === 'scanning';
 
   function handleTabPress(tab: TabVariant) {
+    if (isScanningRoute) {
+      return;
+    }
+
     const href = TAB_TO_HREF[tab];
     if (href) {
       router.navigate(href as any);
@@ -36,6 +60,9 @@ function CustomTabBar({ state }: BottomTabBarProps) {
     <BottomTabBar
       activeTab={activeTab}
       onTabPress={handleTabPress}
+      home={{ disabled: isScanningRoute }}
+      addLink={{ disabled: isScanningRoute }}
+      folder={{ disabled: isScanningRoute }}
     />
   );
 }