Initial commit with Dockerfile and demo code

scripts/dev.mjs

@@ -0,0 +1,64 @@
+/**
+ * Run the server and the web dev server together, with one Ctrl+C to stop both.
+ *
+ * A tiny spawner instead of a dependency like concurrently: two fewer packages to
+ * install, and it behaves predictably on Windows, which is where this demo runs.
+ */
+
+import { spawn } from 'node:child_process';
+import { fileURLToPath } from 'node:url';
+import path from 'node:path';
+
+const root = path.dirname(path.dirname(fileURLToPath(import.meta.url)));
+const npm = process.platform === 'win32' ? 'npm.cmd' : 'npm';
+
+const targets = [
+  { name: 'server', args: ['run', 'dev', '-w', 'server'], color: '\x1b[36m' },
+  { name: 'web', args: ['run', 'dev', '-w', 'web'], color: '\x1b[35m' },
+];
+
+const children = [];
+let shuttingDown = false;
+
+for (const t of targets) {
+  const child = spawn(npm, t.args, { cwd: root, shell: true, stdio: ['ignore', 'pipe', 'pipe'] });
+  children.push(child);
+
+  const prefix = `${t.color}[${t.name}]\x1b[0m `;
+  const pipe = (stream) => {
+    let buf = '';
+    stream.on('data', (chunk) => {
+      buf += chunk.toString();
+      let i;
+      while ((i = buf.indexOf('\n')) >= 0) {
+        const line = buf.slice(0, i);
+        buf = buf.slice(i + 1);
+        if (line.trim()) process.stdout.write(prefix + line + '\n');
+      }
+    });
+  };
+  pipe(child.stdout);
+  pipe(child.stderr);
+
+  child.on('exit', (code) => {
+    if (shuttingDown) return;
+    console.log(`${prefix}exited with code ${code}. Shutting down.`);
+    shutdown();
+  });
+}
+
+function shutdown() {
+  if (shuttingDown) return;
+  shuttingDown = true;
+  for (const c of children) {
+    if (!c.killed) c.kill();
+  }
+  setTimeout(() => process.exit(0), 300);
+}
+
+process.on('SIGINT', shutdown);
+process.on('SIGTERM', shutdown);
+
+console.log('\n  Digital twin demo starting…');
+console.log('  Dashboard: \x1b[1mhttp://localhost:5173\x1b[0m');
+console.log('  API:       http://localhost:8787\n');