Add artifact win condition (#3)

Reviewed-on: #3
Co-authored-by: Malte Langkabel <malte.langkabel@gmail.com>
Co-committed-by: Malte Langkabel <malte.langkabel@gmail.com>

src/lib/config/WorldConfig.h

@@ -47,6 +47,13 @@ struct WorldTargeting
     double  hysteresis;               // fractional margin a challenger must beat the current target by
 };
 
+// Artifact win condition (REQ-WIN-ARTIFACT-COUNT, REQ-WIN-SCREEN).
+struct WorldArtifacts
+{
+    Formula artifactChanceFormula;  // x = station level, result clamped to [0,1]
+    int     artifactWinCount;
+};
+
 struct WorldConfig
 {
     int heightTiles;                    // REQ-GW-HEIGHT
@@ -65,4 +72,5 @@ struct WorldConfig
     WorldPush push;
     WorldWaves waves;
     WorldTargeting targeting;
+    WorldArtifacts artifacts;
 };