Refactor backend into domain-first slices

apps/backend/Universe/Runtime/SpatialRuntimeModels.cs

@@ -0,0 +1,59 @@
+
+namespace SpaceGame.Api.Universe.Runtime;
+
+public sealed class SystemRuntime
+{
+    public required SolarSystemDefinition Definition { get; init; }
+    public required Vector3 Position { get; init; }
+}
+
+public sealed class ResourceNodeRuntime
+{
+    public required string Id { get; init; }
+    public required string SystemId { get; init; }
+    public required Vector3 Position { get; set; }
+    public required string SourceKind { get; init; }
+    public required string ItemId { get; init; }
+    public string? CelestialId { get; set; }
+    public float OrbitRadius { get; init; }
+    public float OrbitPhase { get; init; }
+    public float OrbitInclination { get; init; }
+    public float OreRemaining { get; set; }
+    public float MaxOre { get; init; }
+    public string LastDeltaSignature { get; set; } = string.Empty;
+}
+
+public sealed class CelestialRuntime
+{
+    public required string Id { get; init; }
+    public required string SystemId { get; init; }
+    public required SpatialNodeKind Kind { get; init; }
+    public required Vector3 Position { get; set; }
+    public float LocalSpaceRadius { get; init; }
+    public string? ParentNodeId { get; set; }
+    public string? OccupyingStructureId { get; set; }
+    public string? OrbitReferenceId { get; set; }
+    public string LastDeltaSignature { get; set; } = string.Empty;
+}
+
+public sealed class ShipSpatialStateRuntime
+{
+    public string SpaceLayer { get; set; } = SpaceLayerKinds.LocalSpace;
+    public required string CurrentSystemId { get; set; }
+    public string? CurrentCelestialId { get; set; }
+    public Vector3? LocalPosition { get; set; }
+    public Vector3? SystemPosition { get; set; }
+    public string MovementRegime { get; set; } = MovementRegimeKinds.LocalFlight;
+    public string? DestinationNodeId { get; set; }
+    public ShipTransitRuntime? Transit { get; set; }
+}
+
+public sealed class ShipTransitRuntime
+{
+    public required string Regime { get; init; }
+    public string? OriginNodeId { get; init; }
+    public string? DestinationNodeId { get; init; }
+    public DateTimeOffset? StartedAtUtc { get; set; }
+    public DateTimeOffset? ArrivalDueAtUtc { get; set; }
+    public float Progress { get; set; }
+}