feat: upgrade memory flush system

- Use LLM to summarize discarded context into concise daily memory entries
- Batch trim to half when exceeding max_turns/max_tokens, reducing flush frequency
- Run summarization asynchronously in background thread, no blocking on replies
- Add daily scheduled flush (23:55) as fallback for low-activity days
- Sync trimmed messages back to agent to keep context state consistent

agent/protocol/agent.py

@@ -544,11 +544,15 @@ class Agent:
                     logger.info("[Agent] Cleared Agent message history after executor recovery")
             raise
 
-        # Append only the NEW messages from this execution (thread-safe)
-        # This allows concurrent requests to both contribute to history
+        # Sync executor's messages back to agent (thread-safe).
+        # If the executor trimmed context, its message list is shorter than
+        # original_length, so we must replace rather than append.
         with self.messages_lock:
-            new_messages = executor.messages[original_length:]
-            self.messages.extend(new_messages)
+            self.messages = list(executor.messages)
+            # Track messages added in this run (user query + all assistant/tool messages)
+            # original_length may exceed executor.messages length after trimming
+            trim_adjusted_start = min(original_length, len(executor.messages))
+            self._last_run_new_messages = list(executor.messages[trim_adjusted_start:])
         
         # Store executor reference for agent_bridge to access files_to_send
         self.stream_executor = executor

agent/protocol/agent_stream.py

@@ -201,26 +201,6 @@ class AgentStreamExecutor:
                 logger.info(f"[Agent] 第 {turn} 轮")
                 self._emit_event("turn_start", {"turn": turn})
 
-                # Check if memory flush is needed (before calling LLM)
-                # 使用独立的 flush 阈值（50K tokens 或 20 轮）
-                if self.agent.memory_manager and hasattr(self.agent, 'last_usage'):
-                    usage = self.agent.last_usage
-                    if usage and 'input_tokens' in usage:
-                        current_tokens = usage.get('input_tokens', 0)
-
-                        if self.agent.memory_manager.should_flush_memory(
-                                current_tokens=current_tokens
-                        ):
-                            self._emit_event("memory_flush_start", {
-                                "current_tokens": current_tokens,
-                                "turn_count": self.agent.memory_manager.flush_manager.turn_count
-                            })
-
-                            # TODO: Execute memory flush in background
-                            # This would require async support
-                            logger.info(
-                                f"Memory flush recommended: tokens={current_tokens}, turns={self.agent.memory_manager.flush_manager.turn_count}")
-
                 # Call LLM (enable retry_on_empty for better reliability)
                 assistant_msg, tool_calls = self._call_llm_stream(retry_on_empty=True)
                 final_response = assistant_msg
@@ -473,10 +453,6 @@ class AgentStreamExecutor:
             logger.info(f"[Agent] 🏁 完成 ({turn}轮)")
             self._emit_event("agent_end", {"final_response": final_response})
 
-            # 每轮对话结束后增加计数（用户消息+AI回复=1轮）
-            if self.agent.memory_manager:
-                self.agent.memory_manager.increment_turn()
-
         return final_response
 
     def _call_llm_stream(self, retry_on_empty=True, retry_count=0, max_retries=3,
@@ -501,7 +477,8 @@ class AgentStreamExecutor:
 
         # Prepare messages
         messages = self._prepare_messages()
-        logger.info(f"Sending {len(messages)} messages to LLM")
+        turns = self._identify_complete_turns()
+        logger.info(f"Sending {len(messages)} messages ({len(turns)} turns) to LLM")
 
         # Prepare tool definitions (OpenAI/Claude format)
         tools_schema = None
@@ -655,6 +632,14 @@ class AgentStreamExecutor:
                 error_type = "context overflow" if is_context_overflow else "message format error"
                 logger.error(f"💥 {error_type} detected: {e}")
 
+                # Flush memory before trimming to preserve context that will be lost
+                if is_context_overflow and self.agent.memory_manager:
+                    user_id = getattr(self.agent, '_current_user_id', None)
+                    self.agent.memory_manager.flush_memory(
+                        messages=self.messages, user_id=user_id,
+                        reason="overflow", max_messages=0
+                    )
+
                 # Strategy: try aggressive trimming first, only clear as last resort
                 if is_context_overflow and not _overflow_retry:
                     trimmed = self._aggressive_trim_for_overflow()
@@ -1204,14 +1189,28 @@ class AgentStreamExecutor:
         if not turns:
             return
         
-        # Step 2: 轮次限制 - 保留最近 N 轮
+        # Step 2: 轮次限制 - 超出时裁到 max_turns/2，批量 flush 被裁的轮次
         if len(turns) > self.max_context_turns:
-            removed_turns = len(turns) - self.max_context_turns
-            turns = turns[-self.max_context_turns:]  # 保留最近的轮次
+            keep_count = max(1, self.max_context_turns // 2)
+            removed_count = len(turns) - keep_count
+            
+            # Flush discarded turns to daily memory
+            if self.agent.memory_manager:
+                discarded_messages = []
+                for turn in turns[:removed_count]:
+                    discarded_messages.extend(turn["messages"])
+                if discarded_messages:
+                    user_id = getattr(self.agent, '_current_user_id', None)
+                    self.agent.memory_manager.flush_memory(
+                        messages=discarded_messages, user_id=user_id,
+                        reason="trim", max_messages=0
+                    )
+            
+            turns = turns[-keep_count:]
             
             logger.info(
-                f"💾 上下文轮次超限: {len(turns) + removed_turns} > {self.max_context_turns}，"
-                f"移除最早的 {removed_turns} 轮完整对话"
+                f"💾 上下文轮次超限: {keep_count + removed_count} > {self.max_context_turns}，"
+                f"裁剪至 {keep_count} 轮（移除 {removed_count} 轮）"
             )
 
         # Step 3: Token 限制 - 保留完整轮次
@@ -1248,56 +1247,41 @@ class AgentStreamExecutor:
                 logger.info(f"   重建消息列表: {old_count} -> {len(self.messages)} 条消息")
             return
 
-        # Token limit exceeded - keep complete turns from newest
+        # Token limit exceeded - keep the latest half of turns (same strategy as turn limit)
+        keep_count = max(1, len(turns) // 2)
+        removed_count = len(turns) - keep_count
+        kept_turns = turns[-keep_count:]
+        kept_tokens = sum(self._estimate_turn_tokens(t) for t in kept_turns)
+
         logger.info(
             f"🔄 上下文tokens超限: ~{current_tokens + system_tokens} > {max_tokens}，"
-            f"将按完整轮次移除最早的对话"
+            f"裁剪至 {keep_count} 轮（移除 {removed_count} 轮）"
         )
 
-        # 从最新轮次开始，反向累加（保持完整轮次）
-        kept_turns = []
-        accumulated_tokens = 0
-        min_turns = 3  # 尽量保留至少 3 轮，但不强制（避免超出 token 限制）
+        # Flush discarded turns to daily memory
+        if self.agent.memory_manager:
+            discarded_messages = []
+            for turn in turns[:removed_count]:
+                discarded_messages.extend(turn["messages"])
+            if discarded_messages:
+                user_id = getattr(self.agent, '_current_user_id', None)
+                self.agent.memory_manager.flush_memory(
+                    messages=discarded_messages, user_id=user_id,
+                    reason="trim", max_messages=0
+                )
         
-        for i, turn in enumerate(reversed(turns)):
-            turn_tokens = self._estimate_turn_tokens(turn)
-            turns_from_end = i + 1
-            
-            # 检查是否超出限制
-            if accumulated_tokens + turn_tokens <= available_tokens:
-                kept_turns.insert(0, turn)
-                accumulated_tokens += turn_tokens
-            else:
-                # 超出限制
-                # 如果还没有保留足够的轮次，且这是最后的机会，尝试保留
-                if len(kept_turns) < min_turns and turns_from_end <= min_turns:
-                    # 检查是否严重超出（超出 20% 以上则放弃）
-                    overflow_ratio = (accumulated_tokens + turn_tokens - available_tokens) / available_tokens
-                    if overflow_ratio < 0.2:  # 允许最多超出 20%
-                        kept_turns.insert(0, turn)
-                        accumulated_tokens += turn_tokens
-                        logger.debug(f"   为保留最少轮次，允许超出 {overflow_ratio*100:.1f}%")
-                        continue
-                # 停止保留更早的轮次
-                break
-        
-        # 重建消息列表
         new_messages = []
         for turn in kept_turns:
             new_messages.extend(turn['messages'])
         
         old_count = len(self.messages)
-        old_turn_count = len(turns)
         self.messages = new_messages
-        new_count = len(self.messages)
-        new_turn_count = len(kept_turns)
         
-        if old_count > new_count:
-            logger.info(
-                f"   移除了 {old_turn_count - new_turn_count} 轮对话 "
-                f"({old_count} -> {new_count} 条消息，"
-                f"~{current_tokens + system_tokens} -> ~{accumulated_tokens + system_tokens} tokens)"
-            )
+        logger.info(
+            f"   移除了 {removed_count} 轮对话 "
+            f"({old_count} -> {len(self.messages)} 条消息，"
+            f"~{current_tokens + system_tokens} -> ~{kept_tokens + system_tokens} tokens)"
+        )
 
     def _clear_session_db(self):
         """