fix(storage): 全项目扫描修复——外键约束失效根因与计数一致性

- [根因] 连接池补 PRAGMA foreign_keys=ON：原先仅引导连接开启，运行时池连接 FK 强制从未生效，delete_topic 的 SET NULL / delete_session 的 CASCADE 形同虚设（悬空 topic_id、topics 孤儿残留）
- clear_messages 归零 topics.message_count（原先只清 token 列，/clear 后话题列表显示虚假消息数）
- delete_messages_by_ids 补重算 sessions.user_turn_count（sanitize 删除 user 消息后计数永久偏高）
- compact/replace_active_history 新增 recompute_session_topic_message_counts（重插消息无 topic_id，topics.message_count 漂移）
- switch_topic 三连查与 http 模型选择路由包 spawn_blocking（侧边栏主交互高频路径）
- 新增 3 个测试：FK 生效、clear 归零、user_turn_count 重算

src/command/handlers/switch_topic.rs

@@ -68,10 +68,13 @@ async fn handle_switch_topic(
         .ok_or_else(|| CommandError::new("NO_CHAT_ID", "No chat_id in context"))?;
 
     // 尝试解析为序号
+    // 同步 rusqlite 查询统一移入 blocking 线程池（切换话题是侧边栏主交互）
     let target_topic_id = if let Ok(index) = topic_id.parse::<usize>() {
-        let topics = handler
+        let store = handler.store.clone();
-            .store
+        let session_id_bg = session_id.to_string();
-            .list_topics(session_id)
+        tokio::task::spawn_blocking(move || -> Result<String, CommandError> {
+            let topics = store
+                .list_topics(&session_id_bg)
                 .map_err(|e| CommandError::new("LIST_TOPICS_ERROR", e.to_string()))?;
 
             let index = index.saturating_sub(1);
@@ -85,22 +88,32 @@ async fn handle_switch_topic(
                     ),
                 ));
             }
-        topics[index].id.clone()
+            Ok(topics[index].id.clone())
+        })
+        .await
+        .map_err(|e| CommandError::new("LIST_TOPICS_ERROR", e.to_string()))??
     } else {
         topic_id
     };
 
     // 验证目标话题存在
-    let topic = handler
+    let topic = {
-        .store
+        let store = handler.store.clone();
-        .get_topic(&target_topic_id)
+        let topic_id_bg = target_topic_id.clone();
-        .map_err(|e| CommandError::new("SWITCH_TOPIC_ERROR", e.to_string()))?
+        tokio::task::spawn_blocking(move || {
+            store
+                .get_topic(&topic_id_bg)
+                .map_err(|e| CommandError::new("SWITCH_TOPIC_ERROR", e.to_string()))
+        })
+        .await
+        .map_err(|e| CommandError::new("SWITCH_TOPIC_ERROR", e.to_string()))??
         .ok_or_else(|| {
             CommandError::new(
                 "TOPIC_NOT_FOUND",
                 format!("Topic not found: {}", target_topic_id),
             )
-        })?;
+        })?
+    };
 
     // 如果有 SessionManager，实际切换话题历史
     if let Some(ref session_manager) = handler.session_manager
@@ -113,10 +126,15 @@ async fn handle_switch_topic(
     }
 
     // 使用辅助方法获取消息数量
-    let msg_count = handler
+    let msg_count = {
-        .store
+        let store = handler.store.clone();
-        .get_topic_message_count(&target_topic_id)
+        let topic_id_bg = target_topic_id.clone();
-        .unwrap_or(0);
+        tokio::task::spawn_blocking(move || store.get_topic_message_count(&topic_id_bg))
+            .await
+            .ok()
+            .and_then(|r| r.ok())
+            .unwrap_or(0)
+    };
 
     let message = format!(
         "✓ Switched to topic: {} ({} messages)",

src/gateway/http.rs

@@ -1246,9 +1246,14 @@ pub async fn topic_select_model(
     // 同时取 topic 行自带的 session_id 作为双写目标——不信任请求体中的 session_id，
     // 防止客户端误传导致污染其他 session 的默认模型。
     let store = state.session_manager.store();
-    let topic_session_id = match store.get_topic(&req.topic_id) {
+    let topic_lookup = {
-        Ok(Some(topic)) => topic.session_id,
+        let store_bg = store.clone();
-        Ok(None) => {
+        let topic_id_bg = req.topic_id.clone();
+        tokio::task::spawn_blocking(move || store_bg.get_topic(&topic_id_bg)).await
+    };
+    let topic_session_id = match topic_lookup {
+        Ok(Ok(Some(topic))) => topic.session_id,
+        Ok(Ok(None)) => {
             return (
                 StatusCode::NOT_FOUND,
                 Json(SelectModelResponse {
@@ -1257,12 +1262,17 @@ pub async fn topic_select_model(
                 }),
             );
         }
-        Err(e) => {
+        other => {
+            let err = match other {
+                Ok(Err(e)) => e.to_string(),
+                Err(e) => e.to_string(),
+                _ => unreachable!(),
+            };
             return (
                 StatusCode::INTERNAL_SERVER_ERROR,
                 Json(SelectModelResponse {
                     success: false,
-                    error: Some(format!("failed to load topic: {}", e)),
+                    error: Some(format!("failed to load topic: {}", err)),
                 }),
             );
         }
@@ -1295,7 +1305,17 @@ pub async fn topic_select_model(
     drop(config);
 
     let is_clear = provider.is_none() && model.is_none();
-    if let Err(e) = store.update_topic_model(&req.topic_id, provider.as_deref(), model.as_deref()) {
+    let update_result = {
+        let store_bg = store.clone();
+        let topic_id_bg = req.topic_id.clone();
+        let provider_bg = provider.clone();
+        let model_bg = model.clone();
+        tokio::task::spawn_blocking(move || {
+            store_bg.update_topic_model(&topic_id_bg, provider_bg.as_deref(), model_bg.as_deref())
+        })
+        .await
+    };
+    if let Err(e) = update_result.map_err(|e| e.to_string()).and_then(|r| r.map_err(|e| e.to_string())) {
         return (
             StatusCode::INTERNAL_SERVER_ERROR,
             Json(SelectModelResponse {
@@ -1346,8 +1366,15 @@ pub async fn topic_selected_model(
     // topic 级命中直接返回；miss 时按 topic 行的 session_id 回退 session 级
     let (provider, model) = match state.topic_model_selections.get(&q.topic_id) {
         Some(selection) => selection,
-        None => match state.session_manager.store().get_topic(&q.topic_id) {
+        None => {
-            Ok(Some(topic)) => {
+            // 同步 rusqlite 查询移入 blocking 线程池：本路由在每次打开/切换
+            // 话题且缓存 miss 时被调用，不得阻塞 axum async worker
+            let store = state.session_manager.store().clone();
+            let topic_id_bg = q.topic_id.clone();
+            let topic_lookup =
+                tokio::task::spawn_blocking(move || store.get_topic(&topic_id_bg)).await;
+            match topic_lookup {
+                Ok(Ok(Some(topic))) => {
                     // 双保险：SQLite 有物化值但缓存 miss（理论上不会发生）时回填缓存
                     if topic.provider.is_some() || topic.model.is_some() {
                         state.topic_model_selections.set(
@@ -1362,7 +1389,8 @@ pub async fn topic_selected_model(
                         .unwrap_or((None, None))
                 }
                 _ => (None, None),
-        },
+            }
+        }
     };
     Json(SessionSelectedModelResponse { provider, model })
 }

src/storage/mod.rs

@@ -250,6 +250,11 @@ impl SessionStore {
             // 池内每个连接都必须单独设置。WAL + NORMAL 是 SQLite 官方推荐组合：
             // 消除每次 commit 的 WAL full fsync，仅 checkpoint 时同步。
             c.pragma_update(None, "synchronous", "NORMAL")?;
+            // foreign_keys 同样是 per-connection 且默认关闭。schema 声明的
+            // ON DELETE CASCADE / SET NULL（topics/skill_events/messages 引用
+            // sessions，messages 引用 topics）只有在该 PRAGMA 开启时才执行——
+            // 缺少它会导致删除会话/话题后子表行孤儿残留、消息留下悬空 topic_id。
+            c.pragma_update(None, "foreign_keys", "ON")?;
             Ok(())
         });
         let pool = Pool::builder().max_size(8).build(manager)?;
@@ -684,7 +689,10 @@ impl SessionStore {
         if total > 0 {
             conn.execute(
                 "UPDATE sessions SET message_count =
-                    (SELECT COUNT(*) FROM messages WHERE session_id = ?1)
+                    (SELECT COUNT(*) FROM messages WHERE session_id = ?1),
+                 user_turn_count =
+                    (SELECT COUNT(*) FROM messages
+                     WHERE session_id = ?1 AND role = 'user')
                  WHERE id = ?1",
                 params![session_id],
             )?;
@@ -761,9 +769,11 @@ impl SessionStore {
             ",
             params![session_id, now],
         )?;
-        // token 统计增量列随消息清空归零（消息已全部删除，无需重算）
+        // topics 增量列随消息清空归零（消息已全部删除，无需重算）：
+        // message_count 必须一并归零，否则前端话题列表显示虚假消息数
         conn.execute(
             "UPDATE topics SET
+                message_count = 0,
                 stat_prompt_tokens = 0,
                 stat_completion_tokens = 0,
                 stat_total_tokens = 0,
@@ -1107,6 +1117,9 @@ impl SessionStore {
         tx.commit()?;
         // 会话级压缩重组了消息行（标记/删除/插入摘要），所有 topic 统计可能漂移
         self.recompute_session_topic_usage_stats(session_id)?;
+        // 新插入消息经 INSERT_MESSAGE_SQL 写入（无 topic_id 列），被删的旧行
+        // 可能带 topic_id——按活查询重算 topics.message_count 防漂移
+        self.recompute_session_topic_message_counts(session_id)?;
         Ok(true)
     }
 
@@ -1164,6 +1177,9 @@ impl SessionStore {
         tx.commit()?;
         // 整会话消息被替换，所有 topic 统计可能漂移——重算自愈
         self.recompute_session_topic_usage_stats(session_id)?;
+        // 新插入消息经 INSERT_MESSAGE_SQL 写入（无 topic_id 列），topic 消息数
+        // 按活查询重算防漂移
+        self.recompute_session_topic_message_counts(session_id)?;
         Ok(())
     }
 
@@ -2300,6 +2316,25 @@ impl SessionStore {
         self.recompute_topic_usage_stats(&ids)
     }
 
+    /// 按活查询重算指定 session 下所有 topic 的 message_count（自愈漂移）。
+    ///
+    /// 用于整会话级变更路径（replace_active_history / compact_active_history）：
+    /// 这些路径重插的消息不带 topic_id，被删的旧行可能带 topic_id，
+    /// topics.message_count 增量列无法跟随，必须重算。
+    pub fn recompute_session_topic_message_counts(
+        &self,
+        session_id: &str,
+    ) -> Result<(), StorageError> {
+        let conn = self.pool.get()?;
+        conn.execute(
+            "UPDATE topics SET message_count =
+                (SELECT COUNT(*) FROM messages WHERE topic_id = topics.id)
+             WHERE session_id = ?1",
+            params![session_id],
+        )?;
+        Ok(())
+    }
+
     /// 查询单个 session 的 token 消耗统计（cost 累计 + context 瞬时）。
     ///
     /// 按 `session_id` 精确匹配查询，**不过滤** `sub:%`——专门用于子代理 session

src/storage/tests.rs

@@ -1248,3 +1248,109 @@ fn test_backfill_topic_usage_stats_restores_incremental_columns() {
     let stats = store.batch_topic_token_stats(&[topic.id.as_str()]).unwrap();
     assert_eq!(stats.get(&topic.id).unwrap().total_tokens, 430);
 }
+
+#[test]
+fn test_foreign_keys_enforced_on_pool_connections() {
+    let store = SessionStore::in_memory().unwrap();
+    let session = store.create_cli_session(Some("fk")).unwrap();
+    let topic = store.create_topic(&session.id, "topic-fk", None).unwrap();
+    store
+        .append_message_with_topic(&session.id, Some(&topic.id), &ChatMessage::user("m1"))
+        .unwrap();
+
+    // 删除话题：ON DELETE SET NULL 必须生效（消息保留，topic_id 置空）
+    store.delete_topic(&topic.id).unwrap();
+    let conn = store.pool.get().unwrap();
+    let dangling: i64 = conn
+        .query_row(
+            "SELECT COUNT(*) FROM messages WHERE session_id = ?1 AND topic_id IS NOT NULL",
+            params![session.id],
+            |row| row.get(0),
+        )
+        .unwrap();
+    assert_eq!(dangling, 0, "SET NULL 未生效：删除话题后消息仍持悬空 topic_id");
+    let remaining: i64 = conn
+        .query_row(
+            "SELECT COUNT(*) FROM messages WHERE session_id = ?1",
+            params![session.id],
+            |row| row.get(0),
+        )
+        .unwrap();
+    assert_eq!(remaining, 1, "消息本身应保留，仅 topic_id 置空");
+    drop(conn);
+
+    // 删除会话：topics 行必须级联删除，不得孤儿残留
+    store.delete_session(&session.id).unwrap();
+    let conn = store.pool.get().unwrap();
+    let orphan_topics: i64 = conn
+        .query_row(
+            "SELECT COUNT(*) FROM topics WHERE session_id = ?1",
+            params![session.id],
+            |row| row.get(0),
+        )
+        .unwrap();
+    assert_eq!(orphan_topics, 0, "CASCADE 未生效：删除会话后 topics 孤儿残留");
+}
+
+#[test]
+fn test_clear_messages_resets_topic_message_count() {
+    let store = SessionStore::in_memory().unwrap();
+    let session = store.create_cli_session(Some("clear-count")).unwrap();
+    let topic = store.create_topic(&session.id, "topic-clear", None).unwrap();
+    for i in 1..=3 {
+        store
+            .append_message_with_topic(
+                &session.id,
+                Some(&topic.id),
+                &ChatMessage::user(format!("m{i}")),
+            )
+            .unwrap();
+    }
+    assert_eq!(store.get_topic_message_count(&topic.id).unwrap(), 3);
+
+    store.clear_messages(&session.id).unwrap();
+
+    // 清空后话题消息数必须归零，前端不得显示虚假计数
+    assert_eq!(store.get_topic_message_count(&topic.id).unwrap(), 0);
+    let topic_row = store.get_topic(&topic.id).unwrap().unwrap();
+    assert_eq!(topic_row.message_count, 0);
+}
+
+#[test]
+fn test_delete_messages_by_ids_recomputes_user_turn_count() {
+    let store = SessionStore::in_memory().unwrap();
+    let session = store.create_cli_session(Some("turn-count")).unwrap();
+    let topic = store.create_topic(&session.id, "topic-turn", None).unwrap();
+
+    store
+        .append_message_with_topic(&session.id, Some(&topic.id), &ChatMessage::user("u1"))
+        .unwrap();
+    store
+        .append_message_with_topic(
+            &session.id,
+            Some(&topic.id),
+            &assistant_with_usage("a1", 10, 5, 0, None),
+        )
+        .unwrap();
+    store
+        .append_message_with_topic(&session.id, Some(&topic.id), &ChatMessage::user("u2"))
+        .unwrap();
+
+    let before = store.get_session(&session.id).unwrap().unwrap();
+    assert_eq!(before.user_turn_count, 2);
+
+    // 删除 user 消息（sanitize 场景）：user_turn_count 必须同步重算
+    let msgs = store.load_messages_for_topic(&topic.id, None).unwrap();
+    let user_ids: Vec<String> = msgs
+        .iter()
+        .filter(|m| m.role == "user")
+        .map(|m| m.id.clone())
+        .collect();
+    store
+        .delete_messages_by_ids(&session.id, &user_ids[..1])
+        .unwrap();
+
+    let after = store.get_session(&session.id).unwrap().unwrap();
+    assert_eq!(after.user_turn_count, 1);
+    assert_eq!(after.message_count, 2);
+}