feat(render): unify physical residency accounting

tests/AcDream.App.Tests/Rendering/Residency/ResidencyManagerTests.cs

@@ -343,6 +343,60 @@ public sealed class ResidencyManagerTests
         Assert.Equal(1, journal.Count);
     }
 
+    [Fact]
+    public void DomainSourcesAggregateWithoutCountingMappedAddressSpaceAsRam()
+    {
+        var manager = new ResidencyManager();
+        manager.RegisterDomainSource(new DelegateResidencyDomainSource(
+            ResidencyDomain.PreparedPackage,
+            () => new ResidencyDomainSnapshot(
+                ResidencyDomain.PreparedPackage,
+                EntryCount: 1,
+                OwnerCount: 1,
+                Charges: new ResidencyCharges(
+                    LogicalBytes: 64,
+                    PinnedBytes: 32,
+                    MappedVirtualBytes: 30_000))));
+        manager.RegisterDomainSource(new DelegateResidencyDomainSource(
+            ResidencyDomain.StandaloneTextures,
+            () => new ResidencyDomainSnapshot(
+                ResidencyDomain.StandaloneTextures,
+                EntryCount: 2,
+                OwnerCount: 1,
+                Charges: new ResidencyCharges(
+                    GpuResidentBytes: 128),
+                BudgetBytes: 256,
+                CapacityBytes: 128,
+                UsedBytes: 96,
+                LargestFreeBytes: 16)));
+
+        ResidencySnapshot snapshot = manager.CaptureSnapshot();
+
+        Assert.Equal(64, snapshot.TotalCharges.CommittedCpuBytes);
+        Assert.Equal(30_000, snapshot.TotalCharges.MappedVirtualBytes);
+        Assert.Equal(128, snapshot.TotalCharges.PhysicalGpuBytes);
+        Assert.Equal(
+            16,
+            snapshot.Get(ResidencyDomain.StandaloneTextures)
+                .FragmentedFreeBytes);
+    }
+
+    [Fact]
+    public void OnlyOneCanonicalSourceMayOwnADomain()
+    {
+        var manager = new ResidencyManager();
+        var first = new DelegateResidencyDomainSource(
+            ResidencyDomain.ObjectMeshes,
+            () => default);
+        manager.RegisterDomainSource(first);
+
+        Assert.Throws<InvalidOperationException>(() =>
+            manager.RegisterDomainSource(
+                new DelegateResidencyDomainSource(
+                    ResidencyDomain.ObjectMeshes,
+                    () => default)));
+    }
+
     private static AssetHandle<MeshAsset> Resident(
         ResidencyManager manager,
         ulong id,