fix(images): 规范 OpenAI 图像尺寸参数

apps/api/internal/clients/clients_test.go

@@ -370,10 +370,14 @@ func TestOpenAIClientImageEditUsesMultipartWithMultipleImages(t *testing.T) {
 		ModelType: "image_edit",
 		Model:     "gpt-image-2",
 		Body: map[string]any{
-			"model":   "gpt-image-2",
-			"prompt":  "combine the references",
-			"size":    "1024x1536",
-			"quality": "medium",
+			"model":        "gpt-image-2",
+			"prompt":       "combine the references",
+			"size":         "1024x1536",
+			"quality":      "medium",
+			"aspect_ratio": "2:3",
+			"resolution":   "2K",
+			"width":        1024,
+			"height":       1536,
 			"images": []any{
 				"data:image/png;base64," + base64.StdEncoding.EncodeToString([]byte("image one")),
 				"data:image/jpeg;base64," + base64.StdEncoding.EncodeToString([]byte("image two")),
@@ -406,6 +410,62 @@ func TestOpenAIClientImageEditUsesMultipartWithMultipleImages(t *testing.T) {
 	if _, ok := receivedFields["_metadata"]; ok {
 		t.Fatalf("internal metadata must not be forwarded: %+v", receivedFields)
 	}
+	for _, field := range []string{"aspect_ratio", "resolution", "width", "height"} {
+		if _, ok := receivedFields[field]; ok {
+			t.Fatalf("generic image geometry field %q must not be forwarded: %+v", field, receivedFields)
+		}
+	}
+}
+
+func TestOpenAIClientImageGenerationUsesSizeWithoutGenericGeometryFields(t *testing.T) {
+	var received map[string]any
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if err := json.NewDecoder(r.Body).Decode(&received); err != nil {
+			t.Fatalf("decode image generation body: %v", err)
+		}
+		_ = json.NewEncoder(w).Encode(map[string]any{
+			"data": []any{map[string]any{"b64_json": "aW1hZ2U="}},
+		})
+	}))
+	defer server.Close()
+
+	_, err := (OpenAIClient{HTTPClient: server.Client()}).Run(context.Background(), Request{
+		Kind:      "images.generations",
+		ModelType: "image_generate",
+		Model:     "gpt-image-2",
+		Body: map[string]any{
+			"model":        "gpt-image-2",
+			"prompt":       "draw",
+			"size":         "2048x1152",
+			"quality":      "high",
+			"aspect_ratio": "16:9",
+			"aspectRatio":  "16:9",
+			"resolution":   "2K",
+			"width":        2048,
+			"height":       1152,
+		},
+		Candidate: store.RuntimeModelCandidate{
+			BaseURL:           server.URL,
+			Provider:          "openai",
+			ProviderModelName: "gpt-image-2-vip",
+			ModelType:         "image_generate",
+			Credentials:       map[string]any{"apiKey": "openai-key"},
+		},
+	})
+	if err != nil {
+		t.Fatalf("run OpenAI image generation: %v", err)
+	}
+	if received["model"] != "gpt-image-2-vip" ||
+		received["prompt"] != "draw" ||
+		received["size"] != "2048x1152" ||
+		received["quality"] != "high" {
+		t.Fatalf("unexpected image generation fields: %+v", received)
+	}
+	for _, field := range []string{"aspect_ratio", "aspectRatio", "resolution", "width", "height"} {
+		if _, ok := received[field]; ok {
+			t.Fatalf("generic image geometry field %q must not be forwarded: %+v", field, received)
+		}
+	}
 }
 
 func TestOpenAIClientChatReasoningParamsByProvider(t *testing.T) {

apps/api/internal/clients/openai.go

@@ -65,6 +65,7 @@ func (c OpenAIClient) Run(ctx context.Context, request Request) (Response, error
 		}
 	}
 	body["model"] = upstreamModelName(request.Candidate)
+	normalizeOpenAIImageRequestBody(endpointKind, body)
 	stream := openAIEndpointSupportsStream(endpointKind) && (request.Stream || boolValue(body, "stream"))
 	ensureOpenAIStreamUsage(body, endpointKind, stream)
 	raw, contentType, err := openAIRequestPayload(endpointKind, body, request.Candidate)
@@ -171,6 +172,24 @@ func (c OpenAIClient) Run(ctx context.Context, request Request) (Response, error
 	}, nil
 }
 
+func normalizeOpenAIImageRequestBody(endpointKind string, body map[string]any) {
+	if endpointKind != "images.generations" && endpointKind != "images.edits" {
+		return
+	}
+	// OpenAI image endpoints express output geometry through size. The Gateway
+	// keeps the generic fields for capability validation and billing, but they
+	// are not valid OpenAI wire parameters.
+	for _, key := range []string{
+		"aspect_ratio",
+		"aspectRatio",
+		"resolution",
+		"width",
+		"height",
+	} {
+		delete(body, key)
+	}
+}
+
 func openAIRequestPayload(endpointKind string, body map[string]any, candidate store.RuntimeModelCandidate) ([]byte, string, error) {
 	if endpointKind != "images.edits" {
 		raw, err := json.Marshal(body)