Scaffold flit: PWA + Go CLI for ephemeral E2E file transfer

Ports the yaw/2.1 identity/signaling/WebRTC transport from waste-go to
both a browser PWA (with QR pairing and Web Share Target) and a headless
Go CLI, trimmed to 1:1 ephemeral file transfer only.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

pwa/package.json

@@ -0,0 +1,29 @@
+{
+  "name": "pwa",
+  "private": true,
+  "version": "0.0.0",
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "tsc -b && vite build",
+    "lint": "oxlint",
+    "preview": "vite preview"
+  },
+  "dependencies": {
+    "libsodium-wrappers": "^0.8.4",
+    "qrcode": "^1.5.4",
+    "react": "^19.2.7",
+    "react-dom": "^19.2.7"
+  },
+  "devDependencies": {
+    "@types/libsodium-wrappers": "^0.7.14",
+    "@types/node": "^24.13.2",
+    "@types/qrcode": "^1.5.6",
+    "@types/react": "^19.2.17",
+    "@types/react-dom": "^19.2.3",
+    "@vitejs/plugin-react": "^6.0.3",
+    "oxlint": "^1.71.0",
+    "typescript": "~6.0.2",
+    "vite": "^8.1.1"
+  }
+}