[BUG] Live session details serialize browserVersion as "[object Object]"

What I was trying to do

I was collecting live agent-session diagnostics and expected the details response to identify the actual Chromium version used by the session.

Versions tested

• Steel API 0.5.2
• Chromium 150.0.7871.124
• Node 22.13.0
• Docker on Debian 12, host macOS arm64

Describe the bug

The live session details endpoint returns the literal string "[object Object]" for browserVersion instead of the Chromium version.

To reproduce

1. Start a self-hosted Steel session.
2. Request the live/session details endpoint after the browser is ready.
3. Inspect browserVersion.

Actual behavior

{
  "browserVersion": "[object Object]"
}

Expected behavior

The field should be the browser version string returned by Puppeteer, for example Chrome/150.0.7871.124, or should be omitted if unavailable.

Desktop

• OS: Docker on Debian 12, host macOS arm64
• Browser: Chromium 150.0.7871.124
• Steel API: 0.5.2
• Node: 22.13.0

Smartphone

N/A

Additional context

Returning await browserInstance.version() directly from the CDP service fixed the value locally. A focused test asserts that the exact string is preserved rather than passed through generic object stringification.