Function getVisibleCells

getVisibleCells(
    center: HexCoord,
    range: number,
    map: { width: number; height: number },
): HexCoord[]
Returns all cells visible from center within range steps.

Simple BFS with no cost function — every step counts as 1. Cells beyond range steps are excluded. The center cell is always included (at distance 0). No line-of-sight blocking is applied; add that by filtering the result.
Parameters
- center: HexCoord
- range: number
- map: { width: number; height: number }
Returns HexCoord[]
Example
```
const visible = getVisibleCells(
  offsetToHex(unitCol, unitRow),
  2,
  map,
);
```
- Defined in pathfinding/Pathfinding.ts:258