fix: ship production math

internal/model/game/planet.go

@@ -83,6 +83,19 @@ func PlanetProduction(industry, population float64) float64 {
 	return industry*0.75 + population*0.25
 }
 
+func (p *Planet) ReleaseMaterial(shipMass float64) {
+	if p.Production.Type != ProductionShip || p.Production.Progress == nil {
+		panic("planet is not producing any ships")
+	}
+	p.Material = p.Material.Add(ProducedMaterial(shipMass, float64(*p.Production.Progress)))
+	p.Production.Progress = new(Float)
+	p.Production.ProdUsed = new(Float)
+}
+
+func ProducedMaterial(shipMass, progress float64) float64 {
+	return shipMass * progress
+}
+
 // Производство промышленности
 // TODO: test on real values
 // [x] ind * 5 + ind / res = prod