refactor(backend): align api namespaces and project name

apps/backend/Contracts/World.cs

@@ -0,0 +1,58 @@
+namespace SpaceGame.Api.Contracts;
+
+public sealed record WorldSnapshot(
+  string Label,
+  int Seed,
+  long Sequence,
+  int TickIntervalMs,
+  double OrbitalTimeSeconds,
+  OrbitalSimulationSnapshot OrbitalSimulation,
+  DateTimeOffset GeneratedAtUtc,
+  IReadOnlyList<SystemSnapshot> Systems,
+  IReadOnlyList<CelestialSnapshot> Celestials,
+  IReadOnlyList<ResourceNodeSnapshot> Nodes,
+  IReadOnlyList<StationSnapshot> Stations,
+  IReadOnlyList<ClaimSnapshot> Claims,
+  IReadOnlyList<ConstructionSiteSnapshot> ConstructionSites,
+  IReadOnlyList<MarketOrderSnapshot> MarketOrders,
+  IReadOnlyList<PolicySetSnapshot> Policies,
+  IReadOnlyList<ShipSnapshot> Ships,
+  IReadOnlyList<FactionSnapshot> Factions);
+
+public sealed record WorldDelta(
+  long Sequence,
+  int TickIntervalMs,
+  double OrbitalTimeSeconds,
+  OrbitalSimulationSnapshot OrbitalSimulation,
+  DateTimeOffset GeneratedAtUtc,
+  bool RequiresSnapshotRefresh,
+  IReadOnlyList<SimulationEventRecord> Events,
+  IReadOnlyList<CelestialDelta> Celestials,
+  IReadOnlyList<ResourceNodeDelta> Nodes,
+  IReadOnlyList<StationDelta> Stations,
+  IReadOnlyList<ClaimDelta> Claims,
+  IReadOnlyList<ConstructionSiteDelta> ConstructionSites,
+  IReadOnlyList<MarketOrderDelta> MarketOrders,
+  IReadOnlyList<PolicySetDelta> Policies,
+  IReadOnlyList<ShipDelta> Ships,
+  IReadOnlyList<FactionDelta> Factions,
+  ObserverScope? Scope = null);
+
+public sealed record SimulationEventRecord(
+  string EntityKind,
+  string EntityId,
+  string Kind,
+  string Message,
+  DateTimeOffset OccurredAtUtc,
+  string Family = "simulation",
+  string ScopeKind = "universe",
+  string? ScopeEntityId = null,
+  string Visibility = "public");
+
+public sealed record ObserverScope(
+  string ScopeKind,
+  string? SystemId = null,
+  string? CelestialId = null);
+
+public sealed record OrbitalSimulationSnapshot(
+  double SimulatedSecondsPerRealSecond);