fix: 5 个安全/正确性问题（第三轮）

1. (High) 启动加载历史消息无用户过滤
   → 有 current_user_id 时按用户过滤
2. (High) 长期记忆跨用户共享
   → read_for/write_for 按 user_id 隔离
3. (Medium) 摘要读取无用户过滤 — 待后续
4. (Medium) WeChat API 未检查错误
   → notifyStart 检查 ret!=0
   → getUpdates 检查 ret/errcode
   → post_json 加 error_for_status()
5. (Low) set_auth 未更新 base_url
   → &mut self + 实际赋值

src/main.rs

@@ -62,7 +62,7 @@ async fn main() {
     let memory_store = Arc::new(MemoryStore::new(
         database.as_ref().map(|db| Arc::new(db.pool().clone())),
     ));
-    memory_store.load().await;
+    memory_store.load("").await;
 
     // 文件状态管理器（降级方案）
     let file_state = state::StateManager::new(&config.storage.state_dir);
@@ -195,7 +195,7 @@ async fn cmd_listen(
         }
     };
 
-    let client = WeChatClient::new(Some(auth.base_url.clone()));
+    let mut client = WeChatClient::new(Some(auth.base_url.clone()));
     client
         .set_auth(&auth.token, &auth.account_id, &auth.base_url)
         .await;
@@ -366,7 +366,7 @@ async fn cmd_listen(
             Box::pin(async move {
                 let user_id = session.lock().await.current_user_id.clone();
                 match n.as_str() {
-                    "read_memories" => return Ok(memory_store.read().await),
+                    "read_memories" => return Ok(memory_store.read_for(&user_id).await),
                     "write_memory" => {
                         let params: serde_json::Value =
                             serde_json::from_str(&args).unwrap_or_default();
@@ -374,7 +374,7 @@ async fn cmd_listen(
                         if content.is_empty() {
                             return Ok("请提供 content 参数".to_string());
                         }
-                        return Ok(memory_store.write(content).await);
+                        return Ok(memory_store.write_for(&user_id, content).await);
                     }
                     "read_summaries" => return Ok(context::tools::read_summaries(&session).await),
                     "call_capability" => {
@@ -770,7 +770,7 @@ async fn cmd_send(
 
     let base_url = auth.base_url.clone();
     let account_id = auth.account_id.clone();
-    let client = WeChatClient::new(Some(auth.base_url));
+    let mut client = WeChatClient::new(Some(auth.base_url));
     client
         .set_auth(&auth.token, &auth.account_id, &base_url)
         .await;