feat(#3,#4,#7): add backup/restore, polish labels, and rename bulk actions

src/modals/BackupModal.js

@@ -0,0 +1,54 @@
+import React from 'react';
+import { KeyboardAvoidingView, Modal, Platform, Pressable, ScrollView, Text, TextInput, View } from 'react-native';
+import { styles } from '../styles';
+
+export default function BackupModal({
+  visible,
+  onClose,
+  exportJson,
+  importJson,
+  setImportJson,
+  applyImport,
+}) {
+  return (
+    <Modal visible={visible} animationType="slide" transparent>
+      <View style={styles.modalBackdrop}>
+        <KeyboardAvoidingView behavior={Platform.OS === 'ios' ? 'padding' : undefined} style={styles.modalKeyboardWrap}>
+          <View style={styles.modalCard}>
+            <View style={styles.sectionRow}>
+              <Text style={styles.sectionTitle}>Backup & Restore</Text>
+              <Pressable onPress={onClose}>
+                <Text style={styles.closeText}>Close</Text>
+              </Pressable>
+            </View>
+
+            <ScrollView keyboardShouldPersistTaps="handled" contentContainerStyle={{ paddingBottom: 12 }} showsVerticalScrollIndicator={false}>
+              <Text style={styles.cardTitle}>Export JSON</Text>
+              <Text style={styles.cardMeta}>Copy this JSON and store it safely.</Text>
+              <TextInput
+                style={styles.inputMultiline}
+                multiline
+                value={exportJson}
+                editable={false}
+                selectTextOnFocus
+              />
+              <Text style={styles.cardTitle}>Import JSON</Text>
+              <Text style={styles.cardMeta}>Paste a previous backup. This will replace current data.</Text>
+              <TextInput
+                style={styles.inputMultiline}
+                multiline
+                value={importJson}
+                onChangeText={setImportJson}
+                placeholder="Paste backup JSON here"
+                placeholderTextColor="#6b7280"
+              />
+              <Pressable style={styles.primaryBtn} onPress={applyImport}>
+                <Text style={styles.primaryBtnText}>Import & Replace</Text>
+              </Pressable>
+            </ScrollView>
+          </View>
+        </KeyboardAvoidingView>
+      </View>
+    </Modal>
+  );
+}