init: extract mobile app from bincio_activity

Expo/React Native app with local SQLite archive and bincio-activity sync.

app/_layout.tsx

@@ -0,0 +1,16 @@
+import { Stack } from 'expo-router';
+import { SQLiteProvider } from 'expo-sqlite';
+import { StatusBar } from 'expo-status-bar';
+import { migrateDb } from '@/db';
+import { ThemeProvider } from '@/ThemeContext';
+
+export default function RootLayout() {
+  return (
+    <SQLiteProvider databaseName="bincio.db" onInit={migrateDb}>
+      <ThemeProvider>
+        <StatusBar style="light" />
+        <Stack screenOptions={{ headerShown: false }} />
+      </ThemeProvider>
+    </SQLiteProvider>
+  );
+}