fix: 修复FormData stream未触发的问题，使用pipe触发stream读取

app/api/enhance/route.ts

@@ -296,15 +296,32 @@ 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）
+      // 将FormData转换为Buffer（form-data包是stream，需要pipe或使用getBuffer）
       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("end", () => resolve(Buffer.concat(chunks)));
-        formData.on("error", reject);
+        formData.on("data", (chunk: Buffer) => {
+          chunks.push(chunk);
+        });
+        formData.on("end", () => {
+          console.log("[Enhance API] FormData stream结束，chunks数量:", chunks.length);
+          resolve(Buffer.concat(chunks));
+        });
+        formData.on("error", (error) => {
+          console.error("[Enhance API] FormData stream错误:", error);
+          reject(error);
+        });
+        
+        // 重要：form-data包需要被pipe或手动触发才能开始流式传输
+        // 使用PassThrough来触发stream
+        const { PassThrough } = require("stream");
+        const passThrough = new PassThrough();
+        passThrough.on("data", () => {}); // 忽略数据，我们已经在formData上监听
+        formData.pipe(passThrough);
       });
       
+      console.log("[Enhance API] FormData Buffer转换完成，大小:", formDataBuffer.length, "bytes");
+      
       // 将Buffer转换为Uint8Array用于fetch（更兼容）
       const uint8Array = new Uint8Array(formDataBuffer);