feat(audit): multi-value filters across ManagementService, CLI and Central UI

tests/ScadaLink.CentralUI.Tests/Pages/AuditLogPageExportUrlTests.cs

@@ -74,4 +74,22 @@ public class AuditLogPageExportUrlTests
         Assert.Single(query);
         Assert.Equal("Notification", query["channel"]);
     }
+
+    [Fact]
+    public void BuildExportUrl_MultiValueDimensions_EmitRepeatedParams()
+    {
+        // Task 9: each multi-value dimension emits one repeated query-string key
+        // per selected value so the export endpoint's ParseFilter sees them all.
+        var filter = new AuditLogQueryFilter(
+            Channels: new[] { AuditChannel.ApiOutbound, AuditChannel.DbOutbound },
+            Statuses: new[] { AuditStatus.Failed, AuditStatus.Parked },
+            SourceSiteIds: new[] { "plant-a", "plant-b" });
+
+        var url = AuditLogPage.BuildExportUrl(filter);
+
+        var query = QueryHelpers.ParseQuery(new Uri("http://x" + url).Query);
+        Assert.Equal(new[] { "ApiOutbound", "DbOutbound" }, query["channel"].ToArray());
+        Assert.Equal(new[] { "Failed", "Parked" }, query["status"].ToArray());
+        Assert.Equal(new[] { "plant-a", "plant-b" }, query["site"].ToArray());
+    }
 }