chore(dev): add production preview launcher

scripts/start-preview.js

@@ -0,0 +1,76 @@
+import { spawn, spawnSync } from 'node:child_process';
+import {
+  ensurePortlessProxy,
+  fallbackHost,
+  fallbackUrlHost,
+  forwardChildExit,
+  getLocalServerCommand,
+  getPortlessAppName,
+  openInBrowser,
+  portlessBin,
+  portlessEnv,
+  usePortless,
+  waitForUrlReady,
+} from './local-server-utils.mjs';
+import { resolvePort } from './dev-server-utils.mjs';
+
+const fallbackRequestedPort = Number(process.env.PORT) || 4173;
+
+console.log('Building production preview with corepack yarn build...');
+
+const build = spawnSync('corepack', ['yarn', 'build'], {
+  cwd: process.cwd(),
+  env: process.env,
+  stdio: 'inherit',
+});
+
+if (build.status !== 0) {
+  process.exit(build.status ?? 1);
+}
+
+const command = getLocalServerCommand();
+let args;
+let publicUrl = null;
+
+if (command === portlessBin) {
+  ensurePortlessProxy();
+  const appName = getPortlessAppName();
+
+  publicUrl = `https://${appName}.localhost`;
+  args = [appName, 'vite', 'preview'];
+
+  console.log(`Starting Portless production preview at ${publicUrl}`);
+} else {
+  const port = await resolvePort(fallbackRequestedPort);
+  const fallbackUrl = `http://${fallbackUrlHost}:${port}`;
+
+  args = ['preview', '--host', fallbackHost, '--port', String(port), '--strictPort'];
+
+  if (usePortless) {
+    console.warn(`portless unavailable on this platform, using vite preview directly on ${fallbackUrl}`);
+  } else {
+    console.log(`Starting Vite production preview directly at ${fallbackUrl}`);
+  }
+
+  if (port !== fallbackRequestedPort) {
+    console.log(`Preferred preview port ${fallbackRequestedPort} is busy, so this run will use ${fallbackUrl}.`);
+  }
+}
+
+const child = spawn(command, args, {
+  stdio: 'inherit',
+  env: command === portlessBin ? portlessEnv : process.env,
+});
+
+if (publicUrl && process.env.BROWSER !== 'none') {
+  waitForUrlReady(publicUrl, 30_000)
+    .then(() => {
+      console.log(`Opening ${publicUrl} in browser...`);
+      openInBrowser(publicUrl);
+    })
+    .catch((error) => {
+      console.warn(`Could not auto-open ${publicUrl}: ${error.message}`);
+    });
+}
+
+forwardChildExit(child);