Add shared metadata maps and stage-name helpers

internal/framework/responseschema/registry_test.go

@@ -89,3 +89,20 @@ func TestLookupReturnsSchemaCopy(t *testing.T) {
 		t.Fatalf("expected lookup to return independent schema copy")
 	}
 }
+
+func TestDiagnosticsMapIncludesStableSchemaMetadataShapeForAllSchemas(t *testing.T) {
+	registered := Registered()
+	if len(registered) == 0 {
+		t.Fatalf("expected registered response schemas")
+	}
+
+	for _, schema := range registered {
+		metadataMap := schema.DiagnosticsMap()
+		if metadataMap["id"] != schema.ID ||
+			metadataMap["version"] != schema.Version ||
+			metadataMap["name"] != schema.Name ||
+			metadataMap["sha256"] != schema.SHA256 {
+			t.Fatalf("unexpected diagnostics metadata map for %q: %+v", schema.ID, metadataMap)
+		}
+	}
+}