diff --git a/tests/ScadaLink.CentralUI.Tests/Auth/AuthEndpointsCsrfTests.cs b/tests/ScadaLink.CentralUI.Tests/Auth/AuthEndpointsCsrfTests.cs
index 1ddafa7..ac49d3a 100644
--- a/tests/ScadaLink.CentralUI.Tests/Auth/AuthEndpointsCsrfTests.cs
+++ b/tests/ScadaLink.CentralUI.Tests/Auth/AuthEndpointsCsrfTests.cs
@@ -22,7 +22,11 @@ public class AuthEndpointsCsrfTests
         var builder = WebApplication.CreateBuilder();
         builder.Services.AddRouting();
         builder.Services.AddAntiforgery();
-        var app = builder.Build();
+        // Dispose the host: an undisposed WebApplication leaks its config
+        // PhysicalFileProvider (appsettings reload-watch FileSystemWatcher — a
+        // process-wide macOS run-loop thread) and a ConsoleLoggerProcessor
+        // thread, which keep the test host process alive after the run.
+        using var app = builder.Build();
         app.MapAuthEndpoints();
 
         return ((IEndpointRouteBuilder)app).DataSources
diff --git a/tests/ScadaLink.CentralUI.Tests/Auth/AuthPingEndpointTests.cs b/tests/ScadaLink.CentralUI.Tests/Auth/AuthPingEndpointTests.cs
index 6f7ea54..67cebda 100644
--- a/tests/ScadaLink.CentralUI.Tests/Auth/AuthPingEndpointTests.cs
+++ b/tests/ScadaLink.CentralUI.Tests/Auth/AuthPingEndpointTests.cs
@@ -23,7 +23,11 @@ public class AuthPingEndpointTests
         var builder = WebApplication.CreateBuilder();
         builder.Services.AddRouting();
         builder.Services.AddAntiforgery();
-        var app = builder.Build();
+        // Dispose the host: an undisposed WebApplication leaks its config
+        // PhysicalFileProvider (appsettings reload-watch FileSystemWatcher — a
+        // process-wide macOS run-loop thread) and a ConsoleLoggerProcessor
+        // thread, which keep the test host process alive after the run.
+        using var app = builder.Build();
         app.MapAuthEndpoints();
 
         return ((IEndpointRouteBuilder)app).DataSources
diff --git a/tests/ScadaLink.CentralUI.Tests/Deployment/DebugViewDisposalTests.cs b/tests/ScadaLink.CentralUI.Tests/Deployment/DebugViewDisposalTests.cs
index a76767f..4103184 100644
--- a/tests/ScadaLink.CentralUI.Tests/Deployment/DebugViewDisposalTests.cs
+++ b/tests/ScadaLink.CentralUI.Tests/Deployment/DebugViewDisposalTests.cs
@@ -50,8 +50,11 @@ public class DebugViewDisposalTests : BunitContext
         Services.AddSingleton(comms);
 
         var grpcFactory = new SiteStreamGrpcClientFactory(NullLoggerFactory.Instance);
+        // An empty throwaway provider — these tests never call StartStreamAsync,
+        // so the provider is unused. (Services.BuildServiceProvider() would leak
+        // an undisposed provider.)
         var debugStream = new DebugStreamService(
-            comms, Services.BuildServiceProvider(), grpcFactory,
+            comms, new ServiceCollection().BuildServiceProvider(), grpcFactory,
             NullLogger<DebugStreamService>.Instance);
         Services.AddSingleton(debugStream);
 
diff --git a/tests/ScadaLink.CentralUI.Tests/Deployment/DebugViewStreamRaceTests.cs b/tests/ScadaLink.CentralUI.Tests/Deployment/DebugViewStreamRaceTests.cs
index f7a8937..a09af20 100644
--- a/tests/ScadaLink.CentralUI.Tests/Deployment/DebugViewStreamRaceTests.cs
+++ b/tests/ScadaLink.CentralUI.Tests/Deployment/DebugViewStreamRaceTests.cs
@@ -46,8 +46,11 @@ public class DebugViewStreamRaceTests : BunitContext
         Services.AddSingleton(comms);
 
         var grpcFactory = new SiteStreamGrpcClientFactory(NullLoggerFactory.Instance);
+        // An empty throwaway provider — these tests drive HandleStreamEvent
+        // directly and never call StartStreamAsync, so the provider is unused.
+        // (Services.BuildServiceProvider() would leak an undisposed provider.)
         var debugStream = new DebugStreamService(
-            comms, Services.BuildServiceProvider(), grpcFactory,
+            comms, new ServiceCollection().BuildServiceProvider(), grpcFactory,
             NullLogger<DebugStreamService>.Instance);
         Services.AddSingleton(debugStream);
 
diff --git a/tests/ScadaLink.CentralUI.Tests/Shared/DiffDialogTests.cs b/tests/ScadaLink.CentralUI.Tests/Shared/DiffDialogTests.cs
index 5c742a7..0427133 100644
--- a/tests/ScadaLink.CentralUI.Tests/Shared/DiffDialogTests.cs
+++ b/tests/ScadaLink.CentralUI.Tests/Shared/DiffDialogTests.cs
@@ -14,16 +14,16 @@ namespace ScadaLink.CentralUI.Tests.Shared;
 public class DiffDialogTests : BunitContext
 {
     /// <summary>
-    /// DiffDialog applies/removes a body scroll-lock class via JS interop on
-    /// open/close. CentralUI-023 narrowed those catch blocks so they no longer
-    /// swallow every exception — including bUnit's strict-mode unplanned-call
-    /// exception. Tests that exercise open/close must therefore register the
-    /// body-class calls so they do not surface as harness exceptions.
+    /// DiffDialog applies/removes a body scroll-lock class and focuses the modal
+    /// via JS interop on open/close. Loose mode auto-completes those void calls
+    /// so a path that <c>await</c>s them (e.g. <c>DisposeAsync</c> →
+    /// <c>TryUnlockBodyAsync</c>) resumes instead of hanging on a never-completed
+    /// planned invocation, and no strict-mode unplanned-invocation exception
+    /// surfaces through the narrowed CentralUI-023 catch blocks.
     /// </summary>
     private void SetupBodyLockInterop()
     {
-        JSInterop.SetupVoid("document.body.classList.add", "modal-open");
-        JSInterop.SetupVoid("document.body.classList.remove", "modal-open");
+        JSInterop.Mode = JSRuntimeMode.Loose;
     }
 
     [Fact]