Add the Sandbar mobile companion PWA

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

package.json

@@ -0,0 +1,13 @@
+{
+  "name": "sandbar-mobile",
+  "version": "0.1.0",
+  "description": "Installable companion app for Sandbar: push notifications, on-call actions, monitors and tunnel status.",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "test": "node --test test/*.test.mjs",
+    "icons": "node scripts/make-icons.mjs",
+    "serve": "node scripts/serve.mjs"
+  },
+  "license": "MIT"
+}