fix(site-runtime): resolve SiteRuntime-004..011 — deploy-after-persist, remove reflection, deterministic IDs, non-blocking startup, dedicated script scheduler, config-change detection, semantic trust-model check

tests/ScadaLink.SiteRuntime.Tests/Scripts/ScriptExecutionSchedulerTests.cs

@@ -0,0 +1,47 @@
+using ScadaLink.SiteRuntime;
+using ScadaLink.SiteRuntime.Scripts;
+
+namespace ScadaLink.SiteRuntime.Tests.Scripts;
+
+/// <summary>
+/// SiteRuntime-009: the dedicated script-execution scheduler must run script bodies on
+/// its own dedicated threads, not on the shared .NET thread pool, so blocking script
+/// I/O cannot starve the global pool.
+/// </summary>
+public class ScriptExecutionSchedulerTests
+{
+    [Fact]
+    public async Task Scheduler_RunsWork_OffTheThreadPool()
+    {
+        using var scheduler = new ScriptExecutionScheduler(2);
+
+        bool wasThreadPoolThread = true;
+        string? threadName = null;
+
+        await Task.Factory.StartNew(() =>
+        {
+            wasThreadPoolThread = Thread.CurrentThread.IsThreadPoolThread;
+            threadName = Thread.CurrentThread.Name;
+        }, CancellationToken.None, TaskCreationOptions.DenyChildAttach, scheduler);
+
+        Assert.False(wasThreadPoolThread,
+            "Script work must not run on a shared thread-pool thread.");
+        Assert.StartsWith("script-execution-", threadName);
+    }
+
+    [Fact]
+    public void Scheduler_RespectsConfiguredThreadCount()
+    {
+        using var scheduler = new ScriptExecutionScheduler(4);
+        Assert.Equal(4, scheduler.MaximumConcurrencyLevel);
+    }
+
+    [Fact]
+    public void Scheduler_Shared_ReturnsSameInstanceForOptions()
+    {
+        var options = new SiteRuntimeOptions { ScriptExecutionThreadCount = 3 };
+        var a = ScriptExecutionScheduler.Shared(options);
+        var b = ScriptExecutionScheduler.Shared(options);
+        Assert.Same(a, b);
+    }
+}