feat：进一步优化缓存

src/maisaka/chat_loop_service.py

@@ -650,7 +650,6 @@ class MaisakaChatLoopService:
 
         selected_indices.reverse()
         selected_history = [filtered_history[index] for index in selected_indices]
-        selected_history, _ = MaisakaChatLoopService._hide_early_assistant_messages(selected_history)
         selected_history, _ = drop_orphan_tool_results(selected_history)
         selected_history, _ = normalize_tool_result_order(selected_history)
         tool_message_count = sum(1 for message in selected_history if isinstance(message, ToolResultMessage))
@@ -709,38 +708,3 @@ class MaisakaChatLoopService:
             return resolve_enable_visual_planner()
         return True
 
-    @staticmethod
-    def _hide_early_assistant_messages(
-        selected_history: List[LLMContextMessage],
-    ) -> tuple[List[LLMContextMessage], int]:
-        """隐藏上下文中最早 50% 的 assistant 文本消息，但保留工具调用链路。"""
-
-        assistant_indices = [
-            index
-            for index, message in enumerate(selected_history)
-            if isinstance(message, AssistantMessage)
-        ]
-        hidden_assistant_count = len(assistant_indices) // 2
-        if hidden_assistant_count <= 0:
-            return selected_history, 0
-
-        removed_assistant_indices = set(assistant_indices[:hidden_assistant_count])
-
-        filtered_history: List[LLMContextMessage] = []
-        for index, message in enumerate(selected_history):
-            if index in removed_assistant_indices:
-                if not message.tool_calls:
-                    continue
-                filtered_history.append(
-                    AssistantMessage(
-                        content="",
-                        timestamp=message.timestamp,
-                        tool_calls=list(message.tool_calls),
-                        source_kind=message.source_kind,
-                    )
-                )
-                continue
-            filtered_history.append(message)
-
-        return filtered_history, hidden_assistant_count
-