Function findClosestNote

findClosestNote(
    chart: RpeJson,
    target: Vec2,
    beat: number,
    chartFlipping?: number,
    maxDistance?: number,
):
    | {
        lineIndex: number;
        noteIndex: number;
        position: NotePosition;
        distance: number;
    }
    | null
Find the note closest to a given scene position at a specific beat.

Useful for implementing click-to-select in a chart editor.
Parameters
- chart: RpeJson
  The parsed RPE chart.
- target: Vec2
  Target position in scene pixels.
- beat: number
  Current beat.
- chartFlipping: number = 0
  Chart flipping flags (0–3).
- maxDistance: number = Infinity
  Only consider notes within this pixel radius (default: Infinity).
Returns
    | {
        lineIndex: number;
        noteIndex: number;
        position: NotePosition;
        distance: number;
    }
    | null
The closest note's info, or null if none found within maxDistance.
Example
```
// On mouse click at (mouseX, mouseY):
const hit = findClosestNote(chart, { x: mouseX, y: mouseY }, currentBeat, 0, 30);
if (hit) {
  console.log(`Clicked line ${hit.lineIndex}, note ${hit.noteIndex}`);
}
```
- Defined in position.ts:482