fix(cli): start web dev backend with start command

scripts/dev-server-command.mjs

@@ -1,7 +1,17 @@
-export function createChatlabServeCommand({ serverDir, backendPort, nodeExecutable = process.execPath }) {
+export function createChatlabStartCommand({ serverDir, backendPort, nodeExecutable = process.execPath }) {
   return {
     command: nodeExecutable,
-    args: ['--watch', '--import', 'tsx', 'src/cli.ts', 'serve', '--port', String(backendPort)],
+    args: [
+      '--watch',
+      '--import',
+      'tsx',
+      'src/cli.ts',
+      'start',
+      '--headless',
+      '--no-open',
+      '--port',
+      String(backendPort),
+    ],
     options: {
       cwd: serverDir,
       stdio: ['ignore', 'pipe', 'pipe'],