fix: support grok2 image size constraints for 3:2 and 2:3 aspect ratios

src/lib/generator-api.ts

@@ -26,9 +26,22 @@ const OFFICIAL_ONLY_PROVIDER_KEYS = new Set(['bailian', 'siliconflow'])
 /**
  * 将 aspectRatio 映射为 OpenAI 兼容的 size
  */
-function aspectRatioToOpenAISize(aspectRatio: string | undefined): string | undefined {
+function aspectRatioToOpenAISize(aspectRatio: string | undefined, providerKey?: string): string | undefined {
     if (!aspectRatio) return undefined
     const ratio = aspectRatio.trim()
+
+    // Grok2 支持的尺寸: 1024x1024, 1792x1024, 1024x1792, 1280x720, 720x1280
+    if (providerKey === 'grok2') {
+        const grok2Mapping: Record<string, string> = {
+            '1:1': '1024x1024',
+            '16:9': '1792x1024',
+            '9:16': '1024x1792',
+            '3:2': '1792x1024',  // 使用 1792x1024 代替不支持的 1536x1024
+            '2:3': '1024x1792',  // 使用 1024x1792 代替不支持的 1024x1536
+        }
+        return grok2Mapping[ratio] || undefined
+    }
+
     // OpenAI 支持的尺寸: 1024x1024, 1792x1024, 1024x1792, 1536x1024, 1024x1536
     const mapping: Record<string, string> = {
         '1:1': '1024x1024',
@@ -130,7 +143,7 @@ export async function generateImage(
         // OpenAI 兼容模式：将 aspectRatio 转换为 size
         let openaiCompatOptions = { ...generatorOptions }
         if (openaiCompatOptions.aspectRatio) {
-            const mappedSize = aspectRatioToOpenAISize(openaiCompatOptions.aspectRatio)
+            const mappedSize = aspectRatioToOpenAISize(openaiCompatOptions.aspectRatio, providerKey)
             if (mappedSize && !openaiCompatOptions.size) {
                 openaiCompatOptions = { ...openaiCompatOptions, size: mappedSize }
             }