Add a dependency-free service for the first run

npm ci wants a lockfile, so an agent starting from an empty directory cannot use
the example configuration until it has written a whole npm project. This one
runs a server.js on node's own http module with no install step at all, which
makes the shortest loop that exercises all three servers: write a file, start it,
open it in the browser.

It reads the port from PORT as well as from the argument. An agent writing a
server from scratch reaches for process.env.PORT far more readily than for argv,
and a preview listening on the wrong port fails its health check with nothing in
the log to explain why.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

dev-server-mcp/services.localhost.json

@@ -0,0 +1,28 @@
+{
+  "_comment": [
+    "A first end-to-end configuration, deliberately dependency-free.",
+    "",
+    "'node-app' runs whatever server.js the execution wrote, with node alone and no install step.",
+    "That is the point: npm ci needs a lockfile, so the shortest honest loop for an agent starting",
+    "from an empty directory is a server built on node's own http module. Once that works, move to",
+    "services.example.json, where execution-web installs a real dependency tree.",
+    "",
+    "The service reads its port from PORT as well as from the argument, because an agent writing a",
+    "server from scratch is more likely to reach for process.env.PORT than to parse argv."
+  ],
+  "services": {
+    "node-app": {
+      "command": "node",
+      "args": ["server.js", "${port}"],
+      "cwd": ".",
+      "workspaceMode": "execution",
+      "publicUrl": "http://dev-server-worker:${port}",
+      "healthUrl": "http://127.0.0.1:${port}/",
+      "startupTimeoutMs": 20000,
+      "shutdownTimeoutMs": 5000,
+      "env": {
+        "PORT": "${port}"
+      }
+    }
+  }
+}