Add initial first test screen

ArtisanConnect/components/ui/TabBarBackground.ios.tsx

@@ -0,0 +1,22 @@
+import { useBottomTabBarHeight } from '@react-navigation/bottom-tabs';
+import { BlurView } from 'expo-blur';
+import { StyleSheet } from 'react-native';
+import { useSafeAreaInsets } from 'react-native-safe-area-context';
+
+export default function BlurTabBarBackground() {
+  return (
+    <BlurView
+      // System chrome material automatically adapts to the system's theme
+      // and matches the native tab bar appearance on iOS.
+      tint="systemChromeMaterial"
+      intensity={100}
+      style={StyleSheet.absoluteFill}
+    />
+  );
+}
+
+export function useBottomTabOverflow() {
+  const tabHeight = useBottomTabBarHeight();
+  const { bottom } = useSafeAreaInsets();
+  return tabHeight - bottom;
+}