[Feature Request] Add support for detecting headless browsers

[pioz]

Hi!

I’d like to request support for detecting headless browsers.

For example, Chrome running in headless mode may expose a user agent like this:

Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) HeadlessChrome/143.0.7499.4 Safari/537.36

At the moment, it would be useful to have a simple way to detect this through the gem, for example:

browser.headless?

This could return true when the user agent contains known headless browser identifiers such as HeadlessChrome.

Possible use cases:

• Detecting automated/headless traffic
• Adjusting behavior for browser automation tools
• Improving analytics or request classification
• Handling bots or test environments differently

Example expected behavior:

browser = Browser.new(
  "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) HeadlessChrome/143.0.7499.4 Safari/537.36"
)

browser.chrome?    # true
browser.headless?  # true

Would you be open to adding a headless? method, or something similar, to detect this kind of browser?

Thanks!