fix: check for create permissions

app/(tabs)/_layout.tsx

@@ -1,26 +1,5 @@
-import { Ionicons } from "@expo/vector-icons";
-import { useRouter } from "expo-router";
 import { Icon, Label, NativeTabs } from "expo-router/unstable-native-tabs";
 import React from "react";
-import { StyleSheet, TouchableOpacity, View } from "react-native";
-import { useColorScheme } from "../../hooks/use-color-scheme";
-
-export function DevicesHeader() {
-	const router = useRouter();
-	const isDark = useColorScheme() === "dark";
-	const activityColor = isDark ? "#0A84FF" : "#007AFF";
-
-	return (
-		<View style={styles.headerRight}>
-			<TouchableOpacity
-				onPress={() => router.push("/scan-devices")}
-				style={styles.headerButton}
-			>
-				<Ionicons name="add-circle-outline" size={24} color={activityColor} />
-			</TouchableOpacity>
-		</View>
-	);
-}
 
 export default function TabsLayout() {
 	return (
@@ -36,13 +15,3 @@ export default function TabsLayout() {
 		</NativeTabs>
 	);
 }
-
-const styles = StyleSheet.create({
-	headerRight: {
-		flexDirection: "row",
-		gap: 16,
-	},
-	headerButton: {
-		paddingHorizontal: 8,
-	},
-});

app/_layout.tsx

@@ -2,19 +2,21 @@ import { Ionicons } from '@expo/vector-icons';
 import { Stack, useRouter, useSegments } from 'expo-router';
 import { Text, TouchableOpacity } from 'react-native';
 import { useColorScheme } from '../hooks/use-color-scheme';
-import { AuthProvider } from '../src/context/AuthContext';
+import { AuthProvider, useAuth } from '../src/context/AuthContext';
 
 function DevicesHeader() {
   const router = useRouter();
   const isDark = useColorScheme() === 'dark';
   const activityColor = isDark ? '#0A84FF' : '#007AFF';
+  const { canCreate } = useAuth();
 
   return (
     <TouchableOpacity
       onPress={() => router.push('/scan-devices')}
+      disabled={!canCreate}
       style={{ paddingHorizontal: 8 }}
     >
-      <Ionicons name="add-circle-outline" size={24} color={activityColor} />
+      <Ionicons name="add-circle-outline" size={24} color={canCreate ? activityColor : 'gray'} />
     </TouchableOpacity>
   );
 }