feat: scaffold offline-first mobile app (RN+Expo, expo-sqlite)

Capa API tipada de los 8 endpoints, BD local espejo del bundle + outbox
(operaciones y media) + cursor de sync, motor runSync (PUSH /sync ->
PUSH /media -> PULL bundle?since) con idempotencia por uuid y last-write-wins,
mutaciones de alto nivel (write local + encolar), sesion con token en
SecureStore, conectividad NetInfo y UI minima (Login -> Proyectos -> Detalle).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/components/SyncStatusBar.tsx

@@ -0,0 +1,38 @@
+import React from 'react';
+import { ActivityIndicator, StyleSheet, Text, View } from 'react-native';
+import { OutboxCounts } from '../db/outbox';
+import { useIsOnline } from '../net/connectivity';
+
+export function SyncStatusBar({
+  counts,
+  syncing,
+}: {
+  counts: OutboxCounts;
+  syncing: boolean;
+}) {
+  const online = useIsOnline();
+  const pendientes = counts.pending + counts.mediaPending;
+
+  return (
+    <View style={[styles.bar, { backgroundColor: online ? '#1f6f43' : '#8a6d00' }]}>
+      {syncing && <ActivityIndicator color="#fff" size="small" />}
+      <Text style={styles.text}>
+        {online ? 'En línea' : 'Sin conexión'}
+        {pendientes > 0 ? ` · ${pendientes} en cola` : ' · al día'}
+        {counts.conflict > 0 ? ` · ${counts.conflict} conflicto(s)` : ''}
+        {counts.error > 0 ? ` · ${counts.error} error(es)` : ''}
+      </Text>
+    </View>
+  );
+}
+
+const styles = StyleSheet.create({
+  bar: {
+    flexDirection: 'row',
+    alignItems: 'center',
+    gap: 8,
+    paddingHorizontal: 12,
+    paddingVertical: 8,
+  },
+  text: { color: '#fff', fontSize: 13, fontWeight: '600' },
+});