Refactor development script to use dedicated module

scripts/dev.mjs

@@ -0,0 +1,25 @@
+import { spawn } from "node:child_process";
+
+const commands = [
+  ["API", ["run", "dev", "-w", "@mitwirkung/api"]],
+  ["WEB", ["run", "dev", "-w", "@mitwirkung/web"]],
+];
+
+const children = commands.map(([name, args]) => {
+  const child = spawn("npm", args, { stdio: ["inherit", "pipe", "pipe"] });
+  const forward = (stream, target) => stream.on("data", (data) => {
+    for (const line of data.toString().split("\n")) {
+      if (line) target.write(`[${name}] ${line}\n`);
+    }
+  });
+  forward(child.stdout, process.stdout);
+  forward(child.stderr, process.stderr);
+  return child;
+});
+
+const stop = () => children.forEach((child) => child.kill("SIGTERM"));
+process.on("SIGINT", stop);
+process.on("SIGTERM", stop);
+
+const results = await Promise.all(children.map((child) => new Promise((resolve) => child.on("exit", resolve))));
+process.exit(results.some((code) => code !== 0 && code !== null) ? 1 : 0);