feat(metrics): Add new histograms for chunk latency, results, and sources in AdvisoryAiMetrics

feat(telemetry): Record chunk latency, result count, and source count in AdvisoryAiTelemetry

fix(endpoint): Include telemetry source count in advisory chunks endpoint response

test(metrics): Enhance WebServiceEndpointsTests to validate new metrics for chunk latency, results, and sources

refactor(tests): Update test utilities for Deno language analyzer tests

chore(tests): Add performance tests for AdvisoryGuardrail with scenarios and blocked phrases

docs: Archive Sprint 137 design document for scanner and surface enhancements

src/Scanner/__Tests/StellaOps.Scanner.Analyzers.Lang.Deno.Tests/TestFixtures/DenoWorkspaceTestFixture.cs

@@ -1,5 +1,5 @@
 using StellaOps.Scanner.Analyzers.Lang.Deno.Fixtures;
-using StellaOps.Scanner.Analyzers.Lang.Tests.TestUtilities;
+using StellaOps.Scanner.Analyzers.Lang.Deno.Tests.TestUtilities;
 
 namespace StellaOps.Scanner.Analyzers.Lang.Deno.Tests.TestFixtures;