fix(cli): forward explicit false options on start (#2702)

## Summary

- Serialize `chrome-devtools start` arguments against the CLI defaults.
- Preserve explicit false values such as `--headless=false` as
`--no-headless`.
- Add an end-to-end regression test for the forwarded daemon arguments.

## Problem

The CLI defaults `headless` to true while the MCP server defaults it to
false. The start command parsed an explicit false value correctly, but
then serialized it against the server defaults. Because false matched
the server default, the argument was dropped. The daemon subsequently
reparsed the missing option in CLI mode and restored `headless=true`.

Using the CLI option definitions for serialization keeps the default
compact while forwarding explicit values that differ from the CLI
default.

## Testing

- `npm run test tests/e2e/chrome-devtools-start-stop.test.ts`
- `npm run format`
- `npm run test` (all relevant tests passed; the local full-suite run
only failed the unrelated large full-page screenshot case because Chrome
returned `Page is too large`)

Co-authored-by: Natasha Gorshunova <47688881+nattallius@users.noreply.github.com>

src/bin/chrome-devtools.ts

@@ -155,7 +155,7 @@ y.command(
     ) {
       argv.headless = true;
     }
-    const args = serializeArgs(mcpOptions, argv);
+    const args = serializeArgs(getCliOptions(), argv);
     await start(args, argv.sessionId);
     process.exit(0);
   },

tests/e2e/chrome-devtools-start-stop.test.ts

@@ -79,6 +79,22 @@ describe('chrome-devtools', () => {
     await assertDaemonIsRunning(sessionId);
   });
 
+  it('forwards an explicit headless=false option', async () => {
+    const startResult = await runCli(['start', '--headless=false'], sessionId);
+    assert.strictEqual(
+      startResult.status,
+      0,
+      `start command failed: ${startResult.stderr}`,
+    );
+
+    const statusResult = await runCli(['status'], sessionId);
+    assert.strictEqual(statusResult.status, 0);
+    assert.ok(
+      statusResult.stdout.includes('--no-headless'),
+      `headless=false was not forwarded: ${statusResult.stdout}`,
+    );
+  });
+
   it('can start the daemon with a workspace', async () => {
     const workspace = fs.mkdtempSync(
       path.join(os.tmpdir(), 'chrome-devtools-workspace-'),