fix(wechat): isolate stale images and page links

tkmind-proxy.mjs

@@ -1591,7 +1591,7 @@ export function createTkmindProxy({
 
   async function syncHistoricalImageTurnIsolation(sessionId, activeMessageId) {
     const activeId = String(activeMessageId ?? '').trim();
-    if (!sessionId || !activeId) return;
+    if (!sessionId || !activeId) return { changed: false, updated: false };
     try {
       const target = await resolveTarget(sessionId);
       const upstream = await apiFetch(
@@ -1599,13 +1599,15 @@ export function createTkmindProxy({
         apiSecret,
         `/sessions/${encodeURIComponent(sessionId)}`,
       );
-      if (!upstream.ok) return;
+      if (!upstream.ok) {
+        return { changed: false, updated: false, status: upstream.status };
+      }
       const session = await upstream.json().catch(() => null);
       const { conversation, changed } = scrubConversationHistoricalImageAttachments(
         session?.conversation ?? [],
         activeId,
       );
-      if (!changed) return;
+      if (!changed) return { changed: false, updated: false };
       const update = await apiFetch(
         target,
         apiSecret,
@@ -1619,12 +1621,15 @@ export function createTkmindProxy({
         console.warn(
           `Historical image scrub skipped for session ${sessionId}: upstream ${update.status}`,
         );
+        return { changed: true, updated: false, status: update.status };
       }
+      return { changed: true, updated: true, status: update.status };
     } catch (err) {
       console.warn(
         'Historical image scrub skipped:',
         err instanceof Error ? err.message : err,
       );
+      return { changed: false, updated: false, error: err };
     }
   }
 
@@ -1633,7 +1638,11 @@ export function createTkmindProxy({
     sessionId,
     requestId,
     userMessage,
-    { toolMode = 'chat', forceDeepReasoning = false } = {},
+    {
+      toolMode = 'chat',
+      forceDeepReasoning = false,
+      requireHistoricalImageIsolation = false,
+    } = {},
   ) {
     if (!userId || !sessionId) throw new Error('缺少会话信息');
     const owns = await sessionStore.validateOwnership(userId, sessionId);
@@ -1655,8 +1664,15 @@ export function createTkmindProxy({
 
     const user = await userAuth.getUserById(userId);
     if (!user) throw new Error('用户不存在');
-    if (messageHasImages(userMessage)) {
-      await syncHistoricalImageTurnIsolation(sessionId, userMessage?.id);
+    if (requireHistoricalImageIsolation || messageHasImages(userMessage)) {
+      const imageIsolation = await syncHistoricalImageTurnIsolation(sessionId, userMessage?.id);
+      if (requireHistoricalImageIsolation && imageIsolation.changed && !imageIsolation.updated) {
+        const error = new Error(
+          `historical_image_session_update_unsupported:${imageIsolation.status ?? 'unknown'}`,
+        );
+        error.code = 'HISTORICAL_IMAGE_SESSION_UPDATE_UNSUPPORTED';
+        throw error;
+      }
     }
     let finalUserMessage = userMessage;
     if (llmProviderService && messageHasImages(userMessage) && await llmProviderService.hasVisionKey()) {