修复: checkpoint 参数化 + 压缩 permit 死锁降级 + 密钥归一化 + SSE CRLF/多字节

crates/df-storage/src/crud/conversation_repo.rs

@@ -323,6 +323,40 @@ impl AiToolExecutionRepo {
 // AiConversationRepo 的整体更新已由 impl_repo! 宏统一生成的 update_full 提供。
 
 impl AiConversationRepo {
+    /// 写入对话版本化快照 checkpoint(INSERT OR IGNORE,同 id 已存在则跳过)。
+    ///
+    /// 参数化绑定(替代原调用方的 format! 拼 SQL + execute_batch),防 snapshot 含引号/
+    /// 特殊字符致注入或损坏。列对齐 conversation_checkpoints(id, conv_id, snapshot,
+    /// token_total, created_at)。
+    pub async fn insert_checkpoint(
+        &self,
+        id: &str,
+        conv_id: &str,
+        snapshot: &str,
+        token_total: i64,
+        created_at: &str,
+    ) -> Result<()> {
+        let conn = self.conn.clone();
+        let id = id.to_string();
+        let conv_id = conv_id.to_string();
+        let snapshot = snapshot.to_string();
+        let created_at = created_at.to_string();
+        let _ = tokio::task::spawn_blocking(move || {
+            let guard = conn.blocking_lock();
+            guard
+                .execute(
+                    "INSERT OR IGNORE INTO conversation_checkpoints \
+                     (id, conv_id, snapshot, token_total, created_at) \
+                     VALUES (?1, ?2, ?3, ?4, ?5)",
+                    params![id, conv_id, snapshot, token_total, created_at],
+                )
+                .map_err(storage_err)
+        })
+        .await
+        .map_err(storage_err)??;
+        Ok(())
+    }
+
     /// 清空对话消息内容(保留 conversation 记录本身,只清 messages JSON + 清零 token 计数)
     ///
     /// "清空对话"语义:对话壳保留(侧栏仍可见,可继续在该对话内聊),仅清空历史消息。