优化参数配置逻辑

src/components/composer/GenerationComposer.tsx

@@ -188,13 +188,15 @@ function getSchemaSelectOptions(param: ModelParameter): SchemaSelectOption[] {
 }
 
 function getSelectedSchemaOptionKey(options: SchemaSelectOption[], value: unknown): string | undefined {
+  const normalizedValue = String(value ?? "").toLowerCase();
   return options.find((option) =>
-    Object.is(option.value, value) || String(option.value) === String(value ?? "")
+    Object.is(option.value, value) || String(option.value).toLowerCase() === normalizedValue
   )?.key;
 }
 
 function valueMatchesSchemaOptions(value: unknown, options: string[]): boolean {
-  return options.some((option) => String(option) === String(value));
+  const normalizedValue = String(value ?? "").toLowerCase();
+  return options.some((option) => String(option).toLowerCase() === normalizedValue);
 }
 
 function buildGatewayDimensionSelects(
@@ -207,8 +209,14 @@ function buildGatewayDimensionSelects(
     .filter((param) => nameSet.has(param.name) && param.options && param.options.length > 0)
     .map((parameter) => {
       const options = getSchemaSelectOptions(parameter);
-      const value = draft.parameters?.[parameter.name]
-        ?? options[0]?.value;
+      const value =
+        parameter.name === "resolution"
+          ? draft.resolution
+          : parameter.name === "ratio" || parameter.name === "videoRatio"
+          ? draft.aspectRatio
+          : parameter.name === "duration"
+          ? draft.durationSeconds
+          : draft.parameters?.[parameter.name] ?? options[0]?.value;
       return {
         parameter,
         options,
@@ -217,28 +225,6 @@ function buildGatewayDimensionSelects(
     });
 }
 
-function getSchemaParameterFallbackValue(parameter: ModelParameter): unknown {
-  return parameter.default ?? parameter.options?.[0]?.value ?? parameter.enum?.[0];
-}
-
-function applySchemaParameterDefaults(
-  schema: ModelParameter[] | undefined,
-  parameters: Record<string, unknown> | undefined
-): { parameters: Record<string, unknown>; changed: boolean } {
-  const next = { ...(parameters ?? {}) };
-  let changed = false;
-
-  for (const parameter of schema ?? []) {
-    if (next[parameter.name] !== undefined && next[parameter.name] !== null && next[parameter.name] !== "") continue;
-    const value = getSchemaParameterFallbackValue(parameter);
-    if (value === undefined || value === null || value === "") continue;
-    next[parameter.name] = value;
-    changed = true;
-  }
-
-  return { parameters: next, changed };
-}
-
 function getImageCountOptions(schema: ModelParameter[] | undefined): ImageGenerationCount[] {
   return getSchemaOptionValues(schema, IMAGE_COUNT_PARAMETER_NAMES)
     .map((value) => Number(value))
@@ -602,13 +588,14 @@ function buildPopiserverTaskPricePayload(
   if (!subType) return null;
 
   const aspectRatio =
+    draft.aspectRatio ||
     stringFromUnknown(draft.parameters?.aspectRatio) ||
     stringFromUnknown(draft.parameters?.aspect_ratio) ||
-    draft.aspectRatio ||
     "16:9";
   const dimensions = dimensionsForAspectRatio(aspectRatio);
-  const duration = finiteIntegerFromUnknown(draft.parameters?.duration) ??
-    (type === 2 ? normalizeVideoDurationSeconds(draft.durationSeconds) : null);
+  const duration = type === 2
+    ? normalizeVideoDurationSeconds(draft.durationSeconds)
+    : finiteIntegerFromUnknown(draft.parameters?.duration);
   const modelName = getPopiserverModelName(model);
 
   return {
@@ -620,14 +607,11 @@ function buildPopiserverTaskPricePayload(
     model: modelName,
     aspectRatio,
     ratio: aspectRatio,
-    resolution:
-      stringFromUnknown(draft.parameters?.resolution) ||
-      draft.resolution ||
-      (type === 2 ? DEFAULT_VIDEO_RESOLUTION : "2K"),
+    resolution: draft.resolution || stringFromUnknown(draft.parameters?.resolution) || (type === 2 ? DEFAULT_VIDEO_RESOLUTION : "2K"),
     duration: duration ?? undefined,
-    width: finiteIntegerFromUnknown(draft.parameters?.width) ?? dimensions.width,
-    height: finiteIntegerFromUnknown(draft.parameters?.height) ?? dimensions.height,
-    batchSize: finiteIntegerFromUnknown(draft.parameters?.batchSize) ?? (type === 1 ? draft.imageCount : 1),
+    width: dimensions.width,
+    height: dimensions.height,
+    batchSize: type === 1 ? draft.imageCount : 1,
   };
 }
 
@@ -925,6 +909,20 @@ function readDraftFromContext(context: ComposerContext): ComposerDraft {
   return adapter && context.node ? adapter.readDraft(context.node) : createEmptyDraft();
 }
 
+function composerDraftShallowEqual(a: ComposerDraft, b: ComposerDraft): boolean {
+  return (
+    a.prompt === b.prompt &&
+    a.aspectRatio === b.aspectRatio &&
+    a.resolution === b.resolution &&
+    a.selectedModel === b.selectedModel &&
+    a.inputImages === b.inputImages &&
+    a.imageCount === b.imageCount &&
+    a.durationSeconds === b.durationSeconds &&
+    a.soundEnabled === b.soundEnabled &&
+    a.parameters === b.parameters
+  );
+}
+
 function nodeDraftFingerprint(context: ComposerContext): string {
   if (context.mode !== "node-edit" || !context.node) return contextIdentity(context);
   const data = context.node.data as NanoBananaNodeData | GenerateVideoNodeData | GenerateAudioNodeData;
@@ -1051,6 +1049,7 @@ export function GenerationComposer() {
   const identity = contextIdentity(context);
   const fingerprint = nodeDraftFingerprint(context);
   const [draft, setDraft] = useState(() => readDraftFromContext(context));
+  const [draftIdentity, setDraftIdentity] = useState(() => identity);
   const [dirtyFields, setDirtyFields] = useState<Set<DraftField>>(() => new Set());
   const [assistMenu, setAssistMenu] = useState<"command" | "reference" | null>(null);
   const [modelDialogOpen, setModelDialogOpen] = useState(false);
@@ -1114,7 +1113,16 @@ export function GenerationComposer() {
 
     flushDraftForContext(previousContext);
     contextRef.current = context;
-    setDraft(readDraftFromContext(context));
+    const nextDraft = readDraftFromContext(context);
+    setDraft((current) => {
+      if (composerDraftShallowEqual(current, nextDraft)) {
+        draftRef.current = current;
+        return current;
+      }
+      draftRef.current = nextDraft;
+      return nextDraft;
+    });
+    setDraftIdentity(identity);
     clearDirtyFields();
   }, [clearDirtyFields, context, flushDraftForContext, identity]);
 
@@ -1123,7 +1131,7 @@ export function GenerationComposer() {
     const nextDraft = readDraftFromContext(context);
     setDraft((current) => {
       const dirty = dirtyFieldsRef.current;
-      return {
+      const mergedDraft = {
         prompt: dirty.has("prompt") ? current.prompt : nextDraft.prompt,
         aspectRatio: dirty.has("aspectRatio") ? current.aspectRatio : nextDraft.aspectRatio,
         resolution: dirty.has("resolution") ? current.resolution : nextDraft.resolution,
@@ -1134,7 +1142,14 @@ export function GenerationComposer() {
         soundEnabled: dirty.has("soundEnabled") ? current.soundEnabled : nextDraft.soundEnabled,
         parameters: dirty.has("parameters") ? current.parameters : nextDraft.parameters,
       };
+      if (composerDraftShallowEqual(current, mergedDraft)) {
+        draftRef.current = current;
+        return current;
+      }
+      draftRef.current = mergedDraft;
+      return mergedDraft;
     });
+    setDraftIdentity(identity);
   }, [context, fingerprint]);
 
   const connectedInputs = useMemo(() => {
@@ -1571,20 +1586,6 @@ export function GenerationComposer() {
     ? context.node?.data as NanoBananaNodeData | GenerateVideoNodeData | GenerateAudioNodeData | undefined
     : undefined;
   const activeParameterSchema = generationNodeData?.parameterSchema ?? [];
-  useEffect(() => {
-    if (context.mode !== "node-edit" || !context.node || activeParameterSchema.length === 0) return;
-    const normalized = applySchemaParameterDefaults(activeParameterSchema, draftRef.current.parameters);
-    if (!normalized.changed) return;
-
-    setDraft((current) => {
-      const currentNormalized = applySchemaParameterDefaults(activeParameterSchema, current.parameters);
-      if (!currentNormalized.changed) return current;
-      const next = { ...current, parameters: currentNormalized.parameters };
-      draftRef.current = next;
-      return next;
-    });
-    updateNodeData(context.node.id, { parameters: normalized.parameters });
-  }, [activeParameterSchema, context, updateNodeData]);
   const gatewayDimensionSelects = buildGatewayDimensionSelects(activeParameterSchema, draft);
   const imageCountOptions = getImageCountOptions(activeParameterSchema);
   const visibleImageCountOptions = imageCountOptions.length > 0
@@ -1592,7 +1593,7 @@ export function GenerationComposer() {
     : DEFAULT_IMAGE_COUNT_OPTIONS;
   const imageCountParameterName = getSchemaParameterName(activeParameterSchema, IMAGE_COUNT_PARAMETER_NAMES);
   const selectedImageCountValue = imageCountParameterName
-    ? Number(draft.parameters?.[imageCountParameterName] ?? draft.imageCount)
+    ? draft.imageCount
     : draft.imageCount;
   const videoSoundParameterName = getSchemaParameterName(activeParameterSchema, VIDEO_SOUND_PARAMETER_NAMES);
   const audioVoiceSelect = useMemo(() => {
@@ -1733,11 +1734,18 @@ export function GenerationComposer() {
   }, []);
 
   const updateSchemaDraftParameter = useCallback(
-    (name: string, value: unknown, patch: Partial<ComposerDraft> = {}, fields: DraftField[] = []) => {
+    (
+      name: string,
+      value: unknown,
+      patch: Partial<ComposerDraft> = {},
+      fields: DraftField[] = [],
+      expectedContextIdentity?: string
+    ) => {
       const parameters = updateParameterValue(draftRef.current.parameters, name, value);
       const nextPatch = { ...patch, parameters };
       const updatedFields: DraftField[] = [...fields, "parameters"];
       const activeContext = contextRef.current;
+      if (expectedContextIdentity && contextIdentity(activeContext) !== expectedContextIdentity) return;
 
       setDraft((current) => {
         const next = { ...current, ...nextPatch };
@@ -1770,14 +1778,15 @@ export function GenerationComposer() {
     const resolutionSelect = gatewayDimensionSelects.find((select) => select.parameter.name === "resolution");
     if (
       isProcessNode ||
-      activeCapability !== "image" ||
+      (activeCapability !== "image" && activeCapability !== "video") ||
+      draftIdentity !== identity ||
       !resolutionSelect ||
       resolutionSelect.options.length === 0
     ) {
       return;
     }
 
-    const currentResolution = draft.parameters?.[resolutionSelect.parameter.name] ?? draft.resolution;
+    const currentResolution = draft.resolution ?? draft.parameters?.[resolutionSelect.parameter.name];
     if (valueMatchesSchemaOptions(
       currentResolution,
       resolutionSelect.options.map((option) => String(option.value))
@@ -1792,14 +1801,17 @@ export function GenerationComposer() {
       resolutionSelect.parameter.name,
       nextResolution,
       { resolution: String(nextResolution) },
-      ["resolution"]
+      ["resolution"],
+      identity
     );
   }, [
     activeCapability,
     activeParameterSchema,
     draft.parameters,
     draft.resolution,
+    draftIdentity,
     gatewayDimensionSelects,
+    identity,
     isProcessNode,
     updateSchemaDraftParameter,
   ]);
@@ -1832,6 +1844,8 @@ export function GenerationComposer() {
       const activeContext = contextRef.current;
       const nextResolution = modelSupportsCapability(nextModel, "video")
         ? DEFAULT_VIDEO_RESOLUTION
+        : modelSupportsCapability(nextModel, "image")
+        ? "2K"
         : draftRef.current.resolution;
 
       if (activeContext.mode === "node-edit") {
@@ -1857,11 +1871,13 @@ export function GenerationComposer() {
               ? DEFAULT_VIDEO_DURATION_SECONDS
               : draftRef.current.durationSeconds,
             soundEnabled: getDefaultVideoSoundEnabled(nextModel),
+            parameters: {},
           },
-          new Set<DraftField>(["selectedModel"])
+          new Set<DraftField>(["selectedModel", "resolution", "parameters"])
         );
         updateNodeData(activeContext.node.id, modelPatch);
-        setDraft((current) => ({
+        setDraft((current) => {
+          const next = {
             ...current,
             selectedModel: nextModel,
             resolution: nextResolution,
@@ -1870,24 +1886,33 @@ export function GenerationComposer() {
               : current.durationSeconds,
             soundEnabled: getDefaultVideoSoundEnabled(nextModel),
             parameters: {},
-        }));
+          };
+          draftRef.current = next;
+          return next;
+        });
         clearDirtyFields();
         return;
       }
 
       if (activeContext.mode === "empty-create") {
-        setDraft((current) => ({
+        setDraft((current) => {
+          const next = {
             ...current,
             selectedModel: nextModel,
             resolution: modelSupportsCapability(nextModel, "video")
               ? DEFAULT_VIDEO_RESOLUTION
+              : modelSupportsCapability(nextModel, "image")
+              ? "2K"
               : current.resolution,
             durationSeconds: modelSupportsCapability(nextModel, "video")
               ? DEFAULT_VIDEO_DURATION_SECONDS
               : current.durationSeconds,
             soundEnabled: getDefaultVideoSoundEnabled(nextModel),
             parameters: {},
-        }));
+          };
+          draftRef.current = next;
+          return next;
+        });
       }
     },
     [clearDirtyFields, updateNodeData]

src/components/nodes/GenerateAudioNode.tsx

@@ -25,7 +25,6 @@ import { useI18n } from "@/i18n";
 import { formatUserFacingError } from "@/utils/userFacingErrors";
 import { chooseModelFromList, shouldUpdateSelectedModelFromProviderModel, toSelectedModel } from "@/utils/modelSelection";
 import { useModelStore } from "@/store/modelStore";
-import { buildDefaultParametersFromSchema } from "@/utils/modelSchemaDefaults";
 import { withSpeechVoiceParameter } from "@/utils/speechVoiceParameter";
 
 type GenerateAudioNodeType = Node<GenerateAudioNodeData, "generateAudio">;
@@ -149,7 +148,6 @@ export function GenerateAudioNode({ id, data, selected }: NodeProps<GenerateAudi
       updateNodeData(id, {
         inputSchema: inputs,
         parameterSchema: nextParameterSchema,
-        parameters: buildDefaultParametersFromSchema(nextParameterSchema),
         ...(model && shouldUpdateSelectedModelFromProviderModel(nodeData.selectedModel, model)
           ? { selectedModel: toSelectedModel(model) }
           : {}),

src/components/nodes/GenerateImageNode.tsx

@@ -27,7 +27,6 @@ import { MediaPreviewModal } from "@/components/MediaPreviewModal";
 import { createGeminiLegacyImageModel } from "@/store/utils/defaultImageModel";
 import { getProviderDisplayName, isPopiProviderMode, POPI_PROVIDER_ID } from "@/lib/providerMode";
 import { chooseModelFromList, shouldUpdateSelectedModelFromProviderModel, toSelectedModel } from "@/utils/modelSelection";
-import { buildImageDefaultsFromSchema } from "@/utils/modelSchemaDefaults";
 import { useModelStore } from "@/store/modelStore";
 import {
   isBrowserFileSystemPath,
@@ -516,11 +515,9 @@ export function GenerateImageNode({ id, data, selected }: NodeProps<NanoBananaNo
     enabled: Boolean(nodeData.selectedModel?.modelId) && !usesFirstClassImageControls && canFetchPopiModelSchema,
     refreshKey: nodeData.modelSchemaRequestId,
     onLoaded: ({ inputs, parameters, model }) => {
-      const schemaDefaults = buildImageDefaultsFromSchema(parameters);
       updateNodeData(id, {
         inputSchema: inputs,
         parameterSchema: parameters,
-        ...schemaDefaults,
         ...(model && shouldUpdateSelectedModelFromProviderModel(nodeData.selectedModel, model)
           ? { selectedModel: toSelectedModel(model) }
           : {}),

src/components/nodes/GenerateVideoNode.tsx

@@ -27,7 +27,6 @@ import { useI18n } from "@/i18n";
 import { MediaPreviewModal } from "@/components/MediaPreviewModal";
 import { getProviderDisplayName, isPopiProviderMode, POPI_PROVIDER_ID } from "@/lib/providerMode";
 import { chooseModelFromList, shouldUpdateSelectedModelFromProviderModel, toSelectedModel } from "@/utils/modelSelection";
-import { buildVideoDefaultsFromSchema } from "@/utils/modelSchemaDefaults";
 import { useModelStore } from "@/store/modelStore";
 import { formatUserFacingError } from "@/utils/userFacingErrors";
 import {
@@ -343,11 +342,9 @@ export function GenerateVideoNode({ id, data, selected }: NodeProps<GenerateVide
     enabled: Boolean(nodeData.selectedModel?.modelId) && canFetchPopiModelSchema,
     refreshKey: nodeData.modelSchemaRequestId,
     onLoaded: ({ inputs, parameters, model }) => {
-      const schemaDefaults = buildVideoDefaultsFromSchema(parameters);
       updateNodeData(id, {
         inputSchema: inputs,
         parameterSchema: parameters,
-        ...schemaDefaults,
         ...(model && shouldUpdateSelectedModelFromProviderModel(nodeData.selectedModel, model)
           ? { selectedModel: toSelectedModel(model) }
           : {}),

src/store/execution/generateAudioExecutor.ts

@@ -11,6 +11,7 @@ import { pollGenerateTask } from "./pollTaskCompletion";
 import { runWithFallback } from "./runWithFallback";
 import type { NodeExecutionContext } from "./types";
 import { uploadPopiserverDynamicInputsForGeneration } from "@/utils/temporaryImageUpload";
+import { buildDefaultParametersFromSchema, mergeSchemaDefaults } from "@/utils/modelSchemaDefaults";
 
 export interface GenerateAudioOptions {
   /** When true, falls back to stored inputPrompt if no connections provide it. */
@@ -83,7 +84,10 @@ export async function executeGenerateAudio(
       images: [],
       prompt: text,
       selectedModel: modelToUse,
-      parameters: parametersOverride ?? nodeData.parameters,
+      parameters: mergeSchemaDefaults(
+        buildDefaultParametersFromSchema(nodeData.parameterSchema ?? []),
+        parametersOverride ?? nodeData.parameters
+      ),
       dynamicInputs: preparedDynamicInputs.dynamicInputs,
       mediaType: "audio" as const,
     };

src/store/execution/generateVideoExecutor.ts

@@ -32,7 +32,8 @@ import {
   uploadTemporaryDynamicInputsForGeneration,
   uploadTemporaryImagesForGeneration,
 } from "@/utils/temporaryImageUpload";
-import { mergeConfiguredParameters } from "./generationParameters";
+import { mergeConfiguredParametersOverride } from "./generationParameters";
+import { buildDefaultParametersFromSchema, mergeSchemaDefaults } from "@/utils/modelSchemaDefaults";
 
 export interface GenerateVideoOptions {
   /** When true, falls back to stored inputImages/inputPrompt if no connections provide them. */
@@ -44,13 +45,16 @@ function buildVideoParameters(
   modelToUse: SelectedModel,
   parametersOverride?: Record<string, unknown>
 ): Record<string, unknown> | undefined {
-  const parameters = { ...(parametersOverride ?? nodeData.parameters ?? {}) };
+  const parameters = mergeSchemaDefaults(
+    buildDefaultParametersFromSchema(nodeData.parameterSchema ?? []),
+    parametersOverride ?? nodeData.parameters
+  );
   const durationSeconds = normalizeVideoDurationSeconds(nodeData.durationSeconds);
   const resolution = nodeData.resolution ?? DEFAULT_VIDEO_RESOLUTION;
   const soundParameterName = getVideoSoundParameterName(modelToUse);
 
   if (modelToUse.provider === "popiserver") {
-    const merged = mergeConfiguredParameters(parameters, {
+    const merged = mergeConfiguredParametersOverride(parameters, {
       ...(nodeData.aspectRatio ? { aspectRatio: nodeData.aspectRatio, aspect_ratio: nodeData.aspectRatio } : {}),
       resolution,
       duration: durationSeconds,

src/store/execution/generationParameters.ts

@@ -30,6 +30,19 @@ export function mergeConfiguredParameters(
   return parameters;
 }
 
+export function mergeConfiguredParametersOverride(
+  base: Record<string, unknown> | undefined,
+  configured: Record<string, unknown>
+): Record<string, unknown> {
+  const parameters = { ...(base ?? {}) };
+  for (const [key, value] of Object.entries(configured)) {
+    if (value !== undefined && value !== null) {
+      parameters[key] = value;
+    }
+  }
+  return parameters;
+}
+
 export function resolveImageGenerationCount(
   parameters: Record<string, unknown> | undefined,
   nodeImageCount: number | undefined

src/store/execution/nanoBananaExecutor.ts

@@ -35,10 +35,10 @@ import {
   uploadTemporaryImagesForGeneration,
 } from "@/utils/temporaryImageUpload";
 import {
-  mergeConfiguredParameters,
-  mergeImageGenerationParameters,
+  mergeConfiguredParametersOverride,
   resolveImageGenerationCount,
 } from "./generationParameters";
+import { buildDefaultParametersFromSchema, mergeSchemaDefaults } from "@/utils/modelSchemaDefaults";
 
 export interface NanoBananaOptions {
   /** When true, falls back to stored inputImages/inputPrompt if no connections provide them. */
@@ -166,10 +166,11 @@ export async function executeNanoBanana(
         ...preparedDynamicInputs.cleanupIds,
       ];
 
-      const requestedImageCount = resolveImageGenerationCount(
-        parametersOverride ?? nodeData.parameters,
-        nodeData.imageCount
+      const baseParameters = mergeSchemaDefaults(
+        buildDefaultParametersFromSchema(nodeData.parameterSchema ?? []),
+        parametersOverride ?? nodeData.parameters
       );
+      const requestedImageCount = resolveImageGenerationCount(baseParameters, nodeData.imageCount);
       const configuredParameters = {
         aspectRatio: (parametersOverride?.aspectRatio as string | undefined) ?? nodeData.aspectRatio,
         aspect_ratio: (parametersOverride?.aspectRatio as string | undefined) ?? nodeData.aspectRatio,
@@ -179,12 +180,11 @@ export async function executeNanoBanana(
         useImageSearch: (parametersOverride?.useImageSearch as boolean | undefined) ?? nodeData.useImageSearch,
       };
       const effectiveParameters = provider === "popiserver"
-        ? mergeImageGenerationParameters(
-            parametersOverride ?? nodeData.parameters,
-            configuredParameters,
-            requestedImageCount
-          )
-        : mergeConfiguredParameters(parametersOverride ?? nodeData.parameters, configuredParameters);
+        ? {
+            ...mergeConfiguredParametersOverride(baseParameters, configuredParameters),
+            batchSize: requestedImageCount,
+          }
+        : mergeConfiguredParametersOverride(baseParameters, configuredParameters);
       const requestPayload = {
         images: preparedImages.images,
         prompt: finalPrompt,

src/utils/__tests__/modelSchemaDefaults.test.ts

@@ -0,0 +1,31 @@
+import { describe, expect, it } from "vitest";
+import { mergeSchemaDefaults } from "@/utils/modelSchemaDefaults";
+
+describe("mergeSchemaDefaults", () => {
+  it("fills missing schema defaults without overwriting saved parameters", () => {
+    expect(
+      mergeSchemaDefaults(
+        {
+          resolution: "720p",
+          duration: 5,
+          quality: "standard",
+        },
+        {
+          resolution: "1080p",
+          prompt_strength: 0.8,
+        }
+      )
+    ).toEqual({
+      resolution: "1080p",
+      duration: 5,
+      quality: "standard",
+      prompt_strength: 0.8,
+    });
+  });
+
+  it("returns defaults when there are no saved parameters", () => {
+    expect(mergeSchemaDefaults({ voice: "default" }, undefined)).toEqual({
+      voice: "default",
+    });
+  });
+});

src/utils/modelSchemaDefaults.ts

@@ -26,6 +26,16 @@ export function buildDefaultParametersFromSchema(schema: ModelParameter[]): Reco
   return parameters;
 }
 
+export function mergeSchemaDefaults(
+  defaults: Record<string, unknown>,
+  existing: Record<string, unknown> | undefined
+): Record<string, unknown> {
+  return {
+    ...defaults,
+    ...(existing ?? {}),
+  };
+}
+
 export function buildImageDefaultsFromSchema(schema: ModelParameter[]): {
   aspectRatio?: AspectRatio;
   resolution?: string;