feat: add centered quick-add item button in bottom nav

src/AppRoot.js

@@ -727,6 +727,14 @@ export default function AppRoot() {
     }, 80);
   }
 
+  function openQuickAddItemFromNav() {
+    if (!selectedTripId) {
+      showAlert('No trip selected', 'Please select or create a trip first.');
+      return;
+    }
+    openAddItemModal();
+  }
+
   if (!loaded) {
     return (
       <SafeAreaView style={[styles.safe, { paddingTop: topInset }]}>
@@ -817,7 +825,7 @@ export default function AppRoot() {
         </ScrollView>
       </KeyboardAvoidingView>
 
-      <BottomTab current={tab} onChange={setTab} />
+      <BottomTab current={tab} onChange={setTab} onAddItem={openQuickAddItemFromNav} canAddItem={!!selectedTripId} />
 
       <DatePickerModal
         visible={datePicker.visible}

src/components/BottomTab.js

@@ -3,10 +3,23 @@ import { Pressable, Text, View } from 'react-native';
 import Ionicons from '@expo/vector-icons/Ionicons';
 import { styles } from '../styles';
 
-export default function BottomTab({ current, onChange }) {
-  const tabs = [
+function TabBtn({ tab, current, onChange }) {
+  const active = current === tab.key;
+  return (
+    <Pressable onPress={() => onChange(tab.key)} style={styles.tabItem}>
+      <Ionicons name={active ? tab.iconActive : tab.icon} size={18} color={active ? '#dbeafe' : '#94a3b8'} />
+      <Text style={[styles.tabLabel, active && styles.tabLabelActive]}>{tab.label}</Text>
+    </Pressable>
+  );
+}
+
+export default function BottomTab({ current, onChange, onAddItem, canAddItem }) {
+  const leftTabs = [
     { key: 'trips', label: 'Trips', icon: 'airplane-outline', iconActive: 'airplane' },
     { key: 'items', label: 'Items', icon: 'briefcase-outline', iconActive: 'briefcase' },
+  ];
+
+  const rightTabs = [
     { key: 'checkup', label: 'Check-Up', icon: 'checkmark-circle-outline', iconActive: 'checkmark-circle' },
     { key: 'history', label: 'History', icon: 'time-outline', iconActive: 'time' },
   ];
@@ -14,19 +27,25 @@ export default function BottomTab({ current, onChange }) {
   return (
     <View style={styles.tabBarWrap}>
       <View style={styles.tabBar}>
-        {tabs.map((tab) => {
-          const active = current === tab.key;
-          return (
-            <Pressable key={tab.key} onPress={() => onChange(tab.key)} style={styles.tabItem}>
-              <Ionicons
-                name={active ? tab.iconActive : tab.icon}
-                size={18}
-                color={active ? '#dbeafe' : '#94a3b8'}
-              />
-              <Text style={[styles.tabLabel, active && styles.tabLabelActive]}>{tab.label}</Text>
-            </Pressable>
-          );
-        })}
+        <View style={styles.tabGroupSide}>
+          {leftTabs.map((tab) => (
+            <TabBtn key={tab.key} tab={tab} current={current} onChange={onChange} />
+          ))}
+        </View>
+
+        <Pressable
+          style={[styles.tabAddBtn, !canAddItem && styles.tabAddBtnDisabled]}
+          onPress={onAddItem}
+          disabled={!canAddItem}
+        >
+          <Ionicons name="add" size={26} color="#fff" />
+        </Pressable>
+
+        <View style={styles.tabGroupSide}>
+          {rightTabs.map((tab) => (
+            <TabBtn key={tab.key} tab={tab} current={current} onChange={onChange} />
+          ))}
+        </View>
       </View>
     </View>
   );

src/styles.js

@@ -462,13 +462,34 @@ export const styles = StyleSheet.create({
     borderColor: '#1f2937',
     flexDirection: 'row',
     alignItems: 'center',
+    justifyContent: 'space-between',
+    paddingHorizontal: 8,
+  },
+  tabGroupSide: {
+    flexDirection: 'row',
+    width: '42%',
     justifyContent: 'space-around',
+    alignItems: 'center',
   },
   tabItem: {
     alignItems: 'center',
     justifyContent: 'center',
     gap: 4,
-    minWidth: 62,
+    minWidth: 58,
+  },
+  tabAddBtn: {
+    width: 54,
+    height: 54,
+    borderRadius: 999,
+    alignItems: 'center',
+    justifyContent: 'center',
+    backgroundColor: '#2563eb',
+    marginTop: -24,
+    borderWidth: 2,
+    borderColor: '#0b1220',
+  },
+  tabAddBtnDisabled: {
+    opacity: 0.45,
   },
   tabLabel: {
     color: '#94a3b8',