fix: 修复FormData Buffer转换时chunk类型错误，确保所有chunk都转换为Buffer

app/api/enhance/route.ts

@@ -296,12 +296,22 @@ export async function POST(request: NextRequest) {
       const controller = new AbortController();
       const timeoutId = setTimeout(() => controller.abort(), 60000);
       
-      // 将FormData转换为Buffer（form-data包是stream，需要pipe或使用getBuffer）
+      // 将FormData转换为Buffer（form-data包是stream）
       console.log("[Enhance API] 转换FormData为Buffer...");
       const formDataBuffer = await new Promise<Buffer>((resolve, reject) => {
         const chunks: Buffer[] = [];
-        formData.on("data", (chunk: Buffer) => {
-          chunks.push(chunk);
+        formData.on("data", (chunk: any) => {
+          // 确保chunk是Buffer类型
+          if (Buffer.isBuffer(chunk)) {
+            chunks.push(chunk);
+          } else if (typeof chunk === "string") {
+            chunks.push(Buffer.from(chunk, "utf-8"));
+          } else if (chunk instanceof Uint8Array) {
+            chunks.push(Buffer.from(chunk));
+          } else {
+            console.warn("[Enhance API] 未知的chunk类型:", typeof chunk, chunk);
+            chunks.push(Buffer.from(String(chunk), "utf-8"));
+          }
         });
         formData.on("end", () => {
           console.log("[Enhance API] FormData stream结束，chunks数量:", chunks.length);