Function copyEvents

copyEvents(
    events: Event[],
    sourceStart: number,
    sourceEnd: number,
    targetStart: number,
): Event[]
Duplicate events from one beat range into another beat range.

Only events whose startBeat and endBeat both fall within [sourceStart, sourceEnd] are copied. The copies are shifted so that sourceStart maps to targetStart.
Parameters
- events: Event[]
  Source events (not mutated).
- sourceStart: number
  Start beat of the source range (inclusive).
- sourceEnd: number
  End beat of the source range (inclusive).
- targetStart: number
  Start beat of the target range.
Returns Event[]
New array of cloned and relocated events.
Example
```
// Copy beats 0-8 to start at beat 16
const copies = copyEvents(layer.moveXEvents ?? [], 0, 8, 16);
layer.moveXEvents = [...(layer.moveXEvents ?? []), ...copies];
```
- Defined in events.ts:931