OptionalcontainerDOM container; defaults to document.body.
The player whose schedule is rendered. The panel two-way-binds
to the player: the player's onDateChanged updates the cursor;
dragging the cursor or clicking a milestone calls back into the
player's setDateMs / nextMilestone / play / pause.
OptionalstoragelocalStorage key for persisting drag position + closed state.
Defaults to "xkt-sch-panel".
OptionaltitlePanel title. Defaults to "Schedule".
OptionalvisibleShow on construction (default true).
OptionalxInitial left offset in CSS pixels, applied when supplied.
OptionalyInitial top offset in CSS pixels, applied when supplied.
Constructor parameters for SchedulePanel.