feat: improved visualisation and x4 data import

apps/backend/Contracts/WorldContracts.Celestial.cs

@@ -1,20 +1,36 @@
 namespace SpaceGame.Simulation.Api.Contracts;
 
+public sealed record StarSnapshot(
+  string Kind,
+  string Color,
+  string Glow,
+  float Size,
+  float OrbitRadius,
+  float OrbitSpeed,
+  float OrbitPhaseAtEpoch);
+
+public sealed record MoonSnapshot(
+  string Label,
+  float Size,
+  string Color,
+  float OrbitRadius,
+  float OrbitSpeed,
+  float OrbitPhaseAtEpoch,
+  float OrbitInclination,
+  float OrbitLongitudeOfAscendingNode);
+
 public sealed record SystemSnapshot(
   string Id,
   string Label,
   Vector3Dto GalaxyPosition,
-  string StarKind,
-  int StarCount,
-  string StarColor,
-  float StarSize,
+  IReadOnlyList<StarSnapshot> Stars,
   IReadOnlyList<PlanetSnapshot> Planets);
 
 public sealed record PlanetSnapshot(
   string Label,
   string PlanetType,
   string Shape,
-  int MoonCount,
+  IReadOnlyList<MoonSnapshot> Moons,
   float OrbitRadius,
   float OrbitSpeed,
   float OrbitEccentricity,