Unified Browser Timezone Capability for Selenium 4.10+

The goal is to define a single WebDriver capability that allows test authors to set the browser’s system timezone in a uniform way, independent of the underlying browser or driver implementation.

Currently, Chrome requires the --time-zone command‑line switch, Firefox uses a profile preference, and other browsers expose no standard mechanism, making cross‑browser timezone testing dependent on version‑specific driver options and creating uncertainty about how a future Selenium capability would map to these existing mechanisms.

1. Should Selenium introduce a new standardized capability (e.g., timezone) in the W3C WebDriver spec?
2. How would this capability be translated to Chrome’s --time-zone switch and Firefox’s profile preference?
3. What backward‑compatibility considerations exist for existing driver‑specific arguments and Selenium Manager behavior?