refactor: split app into modular src architecture

src/tabs/CheckupTab.js

@@ -0,0 +1,45 @@
+import React from 'react';
+import { Pressable, Text, View } from 'react-native';
+import { styles } from '../styles';
+
+export default function CheckupTab({ checkupSession, answerCheckupYes, openFixModal, createFreshCheckupSession, saveCheckup }) {
+  return (
+    <View style={styles.section}>
+      <View style={styles.sectionRow}>
+        <Text style={styles.sectionTitle}>Check-Up</Text>
+        <Pressable style={styles.secondaryBtnTight} onPress={createFreshCheckupSession}>
+          <Text style={styles.secondaryBtnText}>Restart</Text>
+        </Pressable>
+      </View>
+
+      {checkupSession.length === 0 ? <Text style={styles.muted}>No items for this trip yet.</Text> : null}
+
+      {checkupSession.map((entry) => (
+        <View key={entry.itemId} style={styles.cardSoft}>
+          <Text style={styles.cardTitle}>{entry.name}</Text>
+          <Text style={styles.cardMeta}>{entry.category || 'uncategorized'}</Text>
+          <Text style={styles.cardMeta}>
+            {entry.current.status} · {entry.current.placement}
+            {entry.current.status === 'lent-to' && entry.current.lentTo ? ` · ${entry.current.lentTo}` : ''}
+          </Text>
+
+          <View style={styles.answerRow}>
+            <Pressable style={styles.answerYes} onPress={() => answerCheckupYes(entry.itemId)}>
+              <Text style={styles.answerText}>Yes</Text>
+            </Pressable>
+            <Pressable style={styles.answerNo} onPress={() => openFixModal(entry.itemId)}>
+              <Text style={styles.answerText}>No</Text>
+            </Pressable>
+            <View style={[styles.answerStateDot, entry.confirmed ? styles.answerStateDotOn : null]} />
+          </View>
+        </View>
+      ))}
+
+      {!!checkupSession.length && (
+        <Pressable style={styles.primaryBtn} onPress={saveCheckup}>
+          <Text style={styles.primaryBtnText}>Save Check-Up Snapshot</Text>
+        </Pressable>
+      )}
+    </View>
+  );
+}