Intermediate, fixes a lot of update problems, keeping selection in place when updating planets still broken.

Stars Assistant/Services/PlanetManager.cs

@@ -1,6 +1,9 @@
 using System;
 using System.ComponentModel;
+using System.Reactive;
+using System.Reactive.Disposables;
 using System.Reactive.Linq;
+using System.Reactive.Subjects;
 using DynamicData;
 using DynamicData.Binding;
 using Splat;
@@ -27,10 +30,21 @@ public class PlanetManager : IDisposable, IEnableLogger
                 .Filter(planet => planet.OwnerId == Game.Player.Name)
                 .Transform(planet => new PlayerPlanetViewModel(planet));
 
+    /// <summary>
+    /// Observable subject to trigger when we update the planet cache, allows the
+    /// UI to react to it.
+    /// </summary>
+    private readonly Subject<Unit> _planetsReloadedSubject = new();
+
+    /// <summary>
+    /// Exposes _planetReloadedSubject as IObservable.
+    /// </summary>
+    public IObservable<Unit> PlanetsReloaded => _planetsReloadedSubject.AsObservable();
+
+    
     public PlanetManager() 
     {
         FleetManager fleetManager = Locator.Current.GetService<FleetManager>()!;
-        
     }
 
     /// <summary>
@@ -50,6 +64,7 @@ public class PlanetManager : IDisposable, IEnableLogger
                 innerCache.AddOrUpdate(allPlanets);
             }
         );
+        _planetsReloadedSubject.OnNext(Unit.Default);
     }
 
     /// <summary>
@@ -60,6 +75,7 @@ public class PlanetManager : IDisposable, IEnableLogger
         if (disposing)
         {
             _planets.Dispose();
+            _planetsReloadedSubject.Dispose();
         }
     }