feat(sitecallaudit): query, KPI and detail backend for the Site Calls page

tests/ScadaLink.SiteCallAudit.Tests/SiteCallAuditOptionsTests.cs

@@ -0,0 +1,15 @@
+namespace ScadaLink.SiteCallAudit.Tests;
+
+public class SiteCallAuditOptionsTests
+{
+    [Fact]
+    public void Defaults_AreExpectedValues()
+    {
+        var options = new SiteCallAuditOptions();
+
+        // Stuck threshold mirrors NotificationOutboxOptions.StuckAgeThreshold.
+        Assert.Equal(TimeSpan.FromMinutes(10), options.StuckAgeThreshold);
+        // KPI interval mirrors NotificationOutboxOptions.DeliveredKpiWindow.
+        Assert.Equal(TimeSpan.FromMinutes(1), options.KpiInterval);
+    }
+}