Preserve LLM generation failure metadata

internal/framework/llm/promptkit_client_test.go

@@ -1028,6 +1028,19 @@ func TestPromptKitClientAppliesConfiguredBuiltInTransientRetries(t *testing.T) {
 			if (err != nil) != test.wantErr {
 				t.Fatalf("CompleteStructured() error = %v, want error=%t", err, test.wantErr)
 			}
+			if test.wantErr {
+				var generation *contracts.LLMGenerationError
+				if !errors.As(err, &generation) || generation.FailureKind() != contracts.LLMGenerationFailureProviderStatus {
+					t.Fatalf("generation error = %#v, want provider-status classification", generation)
+				}
+				wantExhausted := test.name == "exhausted"
+				if generation.RetriesExhausted() != wantExhausted {
+					t.Fatalf("retries exhausted = %t, want %t", generation.RetriesExhausted(), wantExhausted)
+				}
+				if wantExhausted && (generation.Attempts() != 2 || generation.StatusCode() != http.StatusServiceUnavailable) {
+					t.Fatalf("exhausted generation = %#v", generation)
+				}
+			}
 			if got := calls.Load(); got != test.wantCalls {
 				t.Fatalf("HTTP calls = %d, want %d", got, test.wantCalls)
 			}
@@ -1373,6 +1386,51 @@ func TestPromptKitClientForwardsConfiguredTransportTimeout(t *testing.T) {
 	}
 }
 
+func TestPromptKitClientClassifiesBuiltInTransportAndMalformedResponses(t *testing.T) {
+	for _, test := range []struct {
+		name      string
+		kind      contracts.LLMGenerationFailureKind
+		roundTrip func(*http.Request) (*http.Response, error)
+	}{
+		{
+			name: "transport",
+			kind: contracts.LLMGenerationFailureTransport,
+			roundTrip: func(*http.Request) (*http.Response, error) {
+				return nil, errors.New("transport unavailable")
+			},
+		},
+		{
+			name: "malformed response",
+			kind: contracts.LLMGenerationFailureMalformedResponse,
+			roundTrip: func(request *http.Request) (*http.Response, error) {
+				return &http.Response{StatusCode: http.StatusOK, Header: make(http.Header), Body: io.NopCloser(strings.NewReader("not-json")), Request: request}, nil
+			},
+		},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			client, err := NewPromptKitClient(PromptKitClientConfig{
+				Assets:     newTestPromptKitAssets(t),
+				HTTPClient: &http.Client{Transport: roundTripFunc(test.roundTrip)},
+				EngineOptions: []promptkit.Option{promptkit.WithProfiles(promptkit.OpenAICompatibleProfile(promptkit.OpenAICompatibleProfileConfig{
+					ID: "default-profile", Endpoint: "http://promptkit.test/v1", Model: "default-model",
+				}))},
+			})
+			if err != nil {
+				t.Fatal(err)
+			}
+			var out map[string]any
+			_, err = client.CompleteStructured(context.Background(), contracts.StructuredCompletionRequest{
+				PromptID: "adapter.test", SessionID: "failure-kind-test",
+				Inputs: contracts.LLMInputSet{"transcript": contracts.NewLLMInputMaterial("transcript", "application/json", []byte(`{"source":true}`), "", "")},
+			}, &out)
+			var generation *contracts.LLMGenerationError
+			if !errors.As(err, &generation) || generation.FailureKind() != test.kind || generation.RetriesExhausted() || generation.Attempts() != 0 {
+				t.Fatalf("generation error = %#v, want kind %q", generation, test.kind)
+			}
+		})
+	}
+}
+
 func TestPromptKitClientClassifiesEmptyStructuredCompletion(t *testing.T) {
 	client := newTestPromptKitClient(t, &fakePromptKitLLM{allowEmpty: true})