fix: 大样图生成偶发失败加固(前端草图压缩1536px+后端超时5xx自动重试)

frontend/src/views/AIRenderView.vue

@@ -308,8 +308,19 @@ function onSketchUpload(e: { file: unknown }) {
   if (!(file instanceof File)) return
   const reader = new FileReader()
   reader.onload = () => {
-    sketchPhoto.value = String(reader.result)
-    ElMessage.success('草图已上传')
+    // 手机原图过大(5~10MB)会导致生图中转超时/拒绝, 统一压至 ≤1536px JPEG
+    const img = new Image()
+    img.onload = () => {
+      const scale = Math.min(1, 1536 / Math.max(img.naturalWidth, img.naturalHeight))
+      const cv = document.createElement('canvas')
+      cv.width = Math.max(1, Math.round(img.naturalWidth * scale))
+      cv.height = Math.max(1, Math.round(img.naturalHeight * scale))
+      cv.getContext('2d')!.drawImage(img, 0, 0, cv.width, cv.height)
+      sketchPhoto.value = cv.toDataURL('image/jpeg', 0.9)
+      ElMessage.success('草图已上传')
+    }
+    img.onerror = () => ElMessage.error('图片读取失败，请重试')
+    img.src = String(reader.result)
   }
   reader.readAsDataURL(file)
 }