Function findStationPoints

findStationPoints(
    body: CelestialBody,
    startJD: number,
    endJD: number,
): StationPoint[]
Find station points (where planet appears to stop) in a date range.
Parameters
- body: CelestialBody
  Celestial body
- startJD: number
  Start of search range
- endJD: number
  End of search range
Returns StationPoint[]
Array of station points
Remarks
A station occurs when the planet's longitude speed crosses zero.
- Station Retrograde: Speed goes from positive to negative
- Station Direct: Speed goes from negative to positive
Example
```
const stations = findStationPoints(CelestialBody.Mercury, jdStart, jdEnd);
for (const station of stations) {
  console.log(`Mercury ${station.type} at ${station.longitude.toFixed(2)}°`);
}
```
- Defined in transits/retrograde-transits.ts:131