feat(testing): implement test workflow engine with YAML suites, taxonomy filtering, and structured results (#790)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/model/orchestrator/services/test-workflow/index.ts

@@ -0,0 +1,12 @@
+export { TestSuiteParser } from './test-suite-parser';
+export { TaxonomyFilterService } from './taxonomy-filter-service';
+export { TestResultReporter } from './test-result-reporter';
+export { TestWorkflowService } from './test-workflow-service';
+export {
+  TestSuiteDefinition,
+  TestRunDefinition,
+  TaxonomyDimension,
+  TaxonomyDefinition,
+  TestResult,
+  TestFailure,
+} from './test-workflow-types';