feat: bootstrap vela UI and gateway workspace

Establish the monorepo, tooling, and starter apps so UI and gateway development can begin from a documented, runnable baseline.

apps/vela-gateway/package.json

@@ -0,0 +1,14 @@
+{
+  "name": "vela-gateway",
+  "private": true,
+  "version": "0.0.0",
+  "description": "Minimal Fastify app for the Vela gateway service.",
+  "scripts": {
+    "dev": "node --watch src/index.js",
+    "start": "node src/index.js",
+    "build": "node -e \"console.log('vela-gateway: no build step required')\""
+  },
+  "dependencies": {
+    "fastify": "^5.2.1"
+  }
+}