fix(scripting): review minors: configured limit in summaries, dispose gate/CTS, validator, docs (fix round 1)

- ScriptLogRateLimiter.LimitPerWindow. The ScriptLogTopicSink and
  VirtualTagActor summaries now print the configured limit, not
  DefaultLimitPerWindow. Tests assert "limit N/window" for a non-default
  N.
- CalculationDriver.Dispose cancels, then takes _evalGate (bounded 2 s)
  and disposes the gate and _evalCts. The pump and timer ticks enter the
  gate through TryEnterEvalGateAsync, which stops cleanly once the
  driver is disposed. Test: Dispose with a 6 s runaway run in flight
  returns promptly, disposes both, and a late trigger is harmless.
- ScriptedAlarmEngine captures _shutdownToken once and disposes
  _shutdownCts in Dispose when every drained task has completed. A task
  stuck past the grace leaves the CTS to the GC. Lifecycle tests assert
  the disposal.
- DraftValidator: CalculationNoEffectiveTrigger is skipped for a
  change-triggered tag whose scriptId does not resolve. That case is
  already CalculationScriptMissing or CalculationScriptNotFound, and
  there are no reads to count. Both existing tests now assert the
  absence (red before the change).
- docs/VirtualTags.md: System.Threading is denied as a whole namespace,
  with an allow-list; the type list is now accurate (Unsafe,
  RuntimeHelpers, and the ForbiddenMembers on System.Type); the resource
  limits section covers the run guard and the allocation budget.
  docs/ScriptEditor.md: accurate deny-list and a new "Runtime safety"
  section covering timeout, refusal, quarantine after 3 timeouts,
  allocation budget, lifting, and rate-limit summaries that appear only
  on the source's next entry after a burst then quiet.

Refs #734

Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Calculation.Tests/CalculationDriverRemediationTests.cs

@@ -50,6 +50,29 @@ public sealed class CalculationDriverRemediationTests
         driver.IsEvaluationIdle.ShouldBeTrue("the calc driver's evaluation pump should have drained");
     }
 
+    /// <summary>Fix round 1 minor: Dispose releases the evaluation gate and its cancellation source — even
+    /// with a runaway run in flight (the guard lets the caller's cancel win, so the awaited run returns
+    /// promptly) — and a trigger arriving after Dispose is harmless.</summary>
+    [Fact]
+    public async Task Dispose_with_a_run_in_flight_disposes_the_eval_gate_and_a_late_trigger_is_harmless()
+    {
+        var (driver, _, _, _) = Build(
+            CalcTag("calc/e/spin", "var v = ctx.GetTag(\"src/a\").Value; var end = System.DateTime.UtcNow.AddSeconds(6); while (System.DateTime.UtcNow < end) { } return 1;"));
+        await driver.InitializeAsync("{}", TestContext.Current.CancellationToken);
+        driver.OnDependencyValue("src/a", 1, StatusGood, DateTime.UtcNow);
+        var deadline = DateTime.UtcNow.AddSeconds(10);
+        while (driver.IsEvaluationIdle && DateTime.UtcNow < deadline) await Task.Delay(5);
+        driver.IsEvaluationIdle.ShouldBeFalse("positive control: a run is in flight when Dispose lands");
+
+        var sw = System.Diagnostics.Stopwatch.StartNew();
+        driver.Dispose();
+        sw.Elapsed.ShouldBeLessThan(TimeSpan.FromSeconds(5), "the caller's cancel releases the awaited run; Dispose is not held for the 6 s spin");
+        driver.EvalResourcesDisposedForTest.ShouldBeTrue();
+
+        Should.NotThrow(() => driver.OnDependencyValue("src/a", 2, StatusGood, DateTime.UtcNow));
+        Should.NotThrow(() => driver.Dispose());
+    }
+
     [Fact]
     public async Task A_compile_failure_is_remembered_and_logged_once_across_repeated_triggers()
     {