feat: add Expo React Native client scaffold

- Expo SDK 54 / React Native 0.81 with expo-router
- Tailscale devcontainer feature for direct device connectivity
- Dev proxy for React Native DevTools access over Tailscale
- EAS build configuration for development/preview/production
- Ona automation for Expo dev server

Co-authored-by: Ona <no-reply@ona.com>

apps/aris-client/eslint.config.js

@@ -0,0 +1,10 @@
+// https://docs.expo.dev/guides/using-eslint/
+const { defineConfig } = require("eslint/config")
+const expoConfig = require("eslint-config-expo/flat")
+
+module.exports = defineConfig([
+	expoConfig,
+	{
+		ignores: ["dist/*"],
+	},
+])