fix(wechat): avoid image_url session poison on report follow-ups

Store image-only WeChat messages without running Agent, scrub assistant image_url history, and retry historical-image failures with text-only prompts.

Co-authored-by: Cursor <cursoragent@cursor.com>

wechat-mp.mjs

@@ -1094,6 +1094,25 @@ export function isWechatHistoricalImageSessionError(message) {
   );
 }
 
+export const WECHAT_IMAGE_STORED_ACK_TEXT =
+  '已收到图片。请直接告诉我接下来要做什么，例如：解读报告并生成页面。';
+
+export function prepareWechatIntentForHistoricalImageRetry(intent) {
+  if (!intent || typeof intent !== 'object') return intent;
+  const imageUrl = String(intent.media?.publicUrl ?? '').trim();
+  const agentText = String(intent.agentText ?? '').trim();
+  if (imageUrl && !agentText.includes(imageUrl)) {
+    intent.agentText = agentText
+      ? `${agentText}\n\n[附件图片]: ${imageUrl}`
+      : `[附件图片]: ${imageUrl}`;
+  }
+  delete intent.media;
+  delete intent.attachment;
+  delete intent.recentMediaItems;
+  delete intent.recentMediaBatchId;
+  return intent;
+}
+
 export function isRecoverableWechatAgentSessionError(message) {
   const normalized = String(message ?? '').trim();
   if (!normalized) return false;
@@ -3157,6 +3176,9 @@ export function createWechatMpService({
         sessionId = route.sessionId;
         await ensureSessionProvider(sessionId);
         await rememberWechatUserContext(sessionId, user, { forceBootstrap: route.isNewSession });
+        if (historicalImageError) {
+          prepareWechatIntentForHistoricalImageRetry(intent);
+        }
         const retryId = crypto.randomUUID();
         const retryStartedAt = Date.now();
         const retryPageContinuation = sessionPageContinuation && !historicalImageError;
@@ -3683,6 +3705,22 @@ export function createWechatMpService({
         };
         intent.agentText = `[图片1]: ${persisted.publicUrl}`;
         rememberRecentMedia(inbound.fromUserName, intent);
+        await persistIntentDetail({ intent, userId: boundUser.userId, rawXmlHash });
+        if (inbound.msgId && typeof userAuth.finishWechatMpMessage === 'function') {
+          await userAuth.finishWechatMpMessage({
+            appId: config.appId,
+            openid: inbound.fromUserName,
+            msgId: inbound.msgId,
+            status: 'done',
+            agentSessionId: null,
+          });
+        }
+        return {
+          ok: true,
+          status: 200,
+          contentType: 'application/xml; charset=utf-8',
+          body: await buildPassiveReplyBody(WECHAT_IMAGE_STORED_ACK_TEXT),
+        };
       } catch (error) {
         await persistIntentDetail({ intent, userId: boundUser.userId, rawXmlHash });
         return {