Creates a new Clock but does not start it — call start.
Duration, warning thresholds, and tick interval.
Returns the total active session time in seconds (pause time excluded).
Elapsed seconds since start was called (less paused time).
Returns the seconds remaining until the planned session end.
Remaining seconds, or 0 if the planned duration has been exceeded.
Registers a callback invoked each time a configured threshold is crossed.
Receives the TimeWarningEvent for the crossed threshold.
Pauses the clock, freezing elapsed time until resume is called.
Resumes the clock after a pause.
Starts the clock. Should be called when the session transitions to ACTIVE.
Stops the clock and clears the internal tick interval.
Tracks active session time and fires configurable time-warning callbacks.