feat: 使用正确的 Gateway API - chat.send

关键修复:
- 之前错误：直接发送 message.inbound 事件
- 现在正确：使用 Gateway 的 chat.send 方法

Gateway API 调用:
{
  "type": "req",
  "method": "chat.send",
  "params": {
    "sessionKey": "wecom:group:chatId",
    "message": "文本内容",
    "attachments": [{"type": "image", "path": "..."}],
    "deliver": true,
    "idempotencyKey": "messageId"
  }
}

会话管理:
- sessionKey 格式：wecom:chatType:chatId
- 例如：wecom:group:123456789 或 wecom:direct:zhangsan
- OpenClaw 会自动创建或复用会话

媒体文件处理:
- 下载企业微信图片/文件
- 保存到本地媒体目录
- 通过 attachments 参数传递给 chat.send

这样才符合 OpenClaw Gateway 协议规范！

electron/main.js

@@ -131,6 +131,7 @@ class WeComConnection {
     }
   }
 
+  // 转发消息到 OpenClaw - 使用 chat.send API
   async forwardMessageToOpenClaw(frame) {
     if (!openclawConnection || !openclawConnection.isConnected) {
       console.log('[WeCom] OpenClaw not connected, skipping forward');
@@ -163,8 +164,11 @@ class WeComConnection {
       text = text.replace(/@\S+/g, '').trim();
     }
 
+    // 构建 sessionKey（格式：wecom:chatType:chatId）
+    const sessionKey = `wecom:${chatType}:${chatId}`;
+
     // 处理媒体文件
-    const mediaList = [];
+    const attachments = [];
     
     // 下载图片
     if (body.image?.url) {
@@ -172,7 +176,11 @@ class WeComConnection {
         console.log('[WeCom] Downloading image:', body.image.url);
         const { buffer } = await downloadFile(body.image.url, body.image.aeskey);
         const saved = await saveMediaFile(buffer, 'image', 'inbound');
-        mediaList.push({ type: 'image', path: saved.path });
+        attachments.push({
+          type: 'image',
+          path: saved.path,
+          contentType: saved.contentType
+        });
         console.log('[WeCom] Image saved:', saved.path);
       } catch (error) {
         console.error('[WeCom] Failed to download image:', error.message);
@@ -185,35 +193,33 @@ class WeComConnection {
         console.log('[WeCom] Downloading file:', body.file.url);
         const { buffer } = await downloadFile(body.file.url, body.file.aeskey);
         const saved = await saveMediaFile(buffer, 'file', 'inbound');
-        mediaList.push({ type: 'file', path: saved.path });
+        attachments.push({
+          type: 'file',
+          path: saved.path,
+          contentType: saved.contentType
+        });
         console.log('[WeCom] File saved:', saved.path);
       } catch (error) {
         console.error('[WeCom] Failed to download file:', error.message);
       }
     }
 
-    // 构建转发消息
-    const openclawMessage = {
-      type: 'event',
-      event: 'message.inbound',
-      payload: {
-        channel: 'wecom',
-        accountId: this.accountId,
-        message: {
-          id: messageId,
-          from: body.from.userid,
-          chatId: chatId,
-          chatType: chatType,
-          text: text,
-          media: mediaList,
-          timestamp: body.create_time || Date.now()
-        },
-        reqId: reqId,
-        botId: this.botId
+    // 使用 chat.send 方法发送消息到 OpenClaw
+    const chatSendMessage = {
+      type: 'req',
+      id: this.nextId(),
+      method: 'chat.send',
+      params: {
+        sessionKey: sessionKey,
+        message: text,
+        attachments: attachments.length > 0 ? attachments : undefined,
+        deliver: true,  // 立即投递到 AI
+        idempotencyKey: messageId  // 使用消息 ID 作为幂等键
       }
     };
 
-    openclawConnection.send(JSON.stringify(openclawMessage));
+    console.log('[OpenClaw] Sending via chat.send:', sessionKey);
+    openclawConnection.send(JSON.stringify(chatSendMessage));
     console.log(`[Forward] WeCom -> OpenClaw: ${messageId}`);
   }
 
@@ -420,7 +426,7 @@ class OpenClawConnection {
       }
     };
 
-    console.log('[OpenClaw] 发送 connect 请求:', JSON.stringify(connectMessage, null, 2));
+    console.log('[OpenClaw] 发送 connect 请求');
     this.send(connectMessage);
   }
 
@@ -625,7 +631,8 @@ function setupIpcHandlers() {
         params: {
           text: text,
           sessionKey: `test_${Date.now()}`,
-          echo: true
+          deliver: true,
+          idempotencyKey: uuidv4()
         }
       };
       console.log('[OpenClaw] Sending test message:', testMessage);