fix: preserve only unseen tool results

s08_context_compact/README.ja.md

@@ -117,12 +117,15 @@ messages = [*messages[:head_end], marker, *messages[tail_start:]]
 
 ## ステップ 3：micro_compact
 
-`micro_compact` は最新の `tool_result` バッチを完全に保持し、さらに以前のバッチから最新 3 件を残します。それより古く 120 文字を超える結果を短くします。保存済みの結果にはファイルパスを残し、それ以外はプレースホルダーに置き換えます。
+`micro_compact` は直近の assistant 応答より後に追加されたすべての `tool_result` を完全に保持し、モデルが各結果を少なくとも 1 回は完全な形で読めるようにします。モデルがすでに読んだ結果については最新 3 件を残し、それより古く 120 文字を超える結果を短くします。保存済みの結果にはファイルパスを残し、それ以外はプレースホルダーに置き換えます。
 
 ![古い結果を置き換える](images/micro-compact.ja.svg)
 
 ```python
-for block in results[:-self.KEEP_RECENT_RESULTS]:
+unseen = self.unseen_tool_result_positions(messages)
+consumed = [entry for entry in results if entry[:2] not in unseen]
+
+for _, _, block in consumed[:-self.KEEP_RECENT_RESULTS]:
     content = str(block.get("content", ""))
     if len(content) <= 120:
         continue
@@ -305,7 +308,7 @@ s01_agent_loop から s05_todo_write までの README.md を読み、
 各ファイルの最上位見出しを比較して、命名の規則をまとめてください。
 ```
 
-このタスクでは少なくとも 5 件のファイル結果が生成されます。最新のバッチと、それ以前の最新 3 件は完全に残り、それより前の長い結果は `[Earlier tool result omitted.]` に変わります。保存済みの結果には保存先のパスが残ります。
+このタスクでは少なくとも 5 件のファイル結果が生成されます。各新規結果はモデルが初めて読むまで完全に保持されます。以降のターンでは、すでに読まれた最新 3 件を残し、それより前の長い結果は `[Earlier tool result omitted.]` に変わります。保存済みの結果には保存先のパスが残ります。
 
 ### 実験 2：大きな結果を保存する
 

s08_context_compact/README.md

@@ -117,12 +117,15 @@ This step controls the number of messages. Tool results inside the retained mess
 
 ## Step 3: micro_compact
 
-`micro_compact` preserves the newest `tool_result` batch in full, then keeps the latest 3 results from earlier batches and shortens older results longer than 120 characters. Persisted results keep their file path; the rest become placeholders:
+`micro_compact` preserves every `tool_result` added after the most recent assistant response, so the model sees each new result in full once. Among results the model has already consumed, it keeps the latest 3 and shortens older results longer than 120 characters. Persisted results keep their file path; the rest become placeholders:
 
 ![Replacing old results](images/micro-compact.en.svg)
 
 ```python
-for block in results[:-self.KEEP_RECENT_RESULTS]:
+unseen = self.unseen_tool_result_positions(messages)
+consumed = [entry for entry in results if entry[:2] not in unseen]
+
+for _, _, block in consumed[:-self.KEEP_RECENT_RESULTS]:
     content = str(block.get("content", ""))
     if len(content) <= 120:
         continue
@@ -305,7 +308,7 @@ Read the README.md files from s01_agent_loop through s05_todo_write.
 Compare their top-level headings and summarize the naming pattern.
 ```
 
-This task produces at least 5 file results. The newest batch and the latest 3 earlier results remain complete, while older long results become `[Earlier tool result omitted.]`. A persisted result retains its saved path.
+This task produces at least 5 file results. Every result remains complete until the model sees it once. On later turns, the latest 3 consumed results remain complete while older long results become `[Earlier tool result omitted.]`. A persisted result retains its saved path.
 
 ### Experiment 2: Persist a Large Result
 

s08_context_compact/README.zh.md

@@ -117,12 +117,15 @@ messages = [*messages[:head_end], marker, *messages[tail_start:]]
 
 ## 第三步：micro_compact
 
-`micro_compact` 会完整保留最新一批 `tool_result`，再保留更早批次中最近 3 条结果；其余超过 120 个字符的旧结果会缩短。已经转存的结果保留文件路径，其他结果只留下占位符：
+`micro_compact` 会完整保留最近一次 assistant 响应之后新增的所有 `tool_result`，确保模型至少完整读取每条新结果一次。对于模型已经读取过的结果，它保留最近 3 条，并缩短其余超过 120 个字符的旧结果。已经转存的结果保留文件路径，其他结果只留下占位符：
 
 ![旧结果替换为占位符](images/micro-compact.svg)
 
 ```python
-for block in results[:-self.KEEP_RECENT_RESULTS]:
+unseen = self.unseen_tool_result_positions(messages)
+consumed = [entry for entry in results if entry[:2] not in unseen]
+
+for _, _, block in consumed[:-self.KEEP_RECENT_RESULTS]:
     content = str(block.get("content", ""))
     if len(content) <= 120:
         continue
@@ -305,7 +308,7 @@ python s08_context_compact/code.py
 比较它们的一级标题，并总结这些标题的命名规律。
 ```
 
-任务会产生至少 5 条文件读取结果。最新一批以及更早批次中最近 3 条结果保持完整，更早且较长的结果会变成 `[Earlier tool result omitted.]`。已经转存的结果会保留保存路径。
+任务会产生至少 5 条文件读取结果。每条新结果在模型首次读取前都会保持完整；后续轮次只保留最近 3 条已读取结果，更早且较长的结果会变成 `[Earlier tool result omitted.]`。已经转存的结果会保留保存路径。
 
 ### 实验二：大结果转存
 

s08_context_compact/code.py

@@ -267,6 +267,23 @@ class ContextCompactor:
                     for block in content)
         )
 
+    @staticmethod
+    def unseen_tool_result_positions(messages: list) -> set[tuple[int, int]]:
+        """Return results added since the model's most recent response."""
+        last_assistant = next(
+            (index for index in range(len(messages) - 1, -1, -1)
+             if messages[index].get("role") == "assistant"),
+            -1,
+        )
+        return {
+            (message_index, block_index)
+            for message_index in range(last_assistant + 1, len(messages))
+            if messages[message_index].get("role") == "user"
+            and isinstance(messages[message_index].get("content"), list)
+            for block_index, block in enumerate(messages[message_index]["content"])
+            if isinstance(block, dict) and block.get("type") == "tool_result"
+        }
+
     def write_transcript(self, messages: list) -> Path:
         self.transcript_dir.mkdir(parents=True, exist_ok=True)
         path = self.transcript_dir / f"transcript_{uuid.uuid4().hex}.jsonl"
@@ -325,26 +342,15 @@ class ContextCompactor:
 
     def micro_compact(self, messages: list) -> list:
         results = [
-            block
-            for message in messages
+            (message_index, block_index, block)
+            for message_index, message in enumerate(messages)
             if message.get("role") == "user" and isinstance(message.get("content"), list)
-            for block in message["content"]
+            for block_index, block in enumerate(message["content"])
             if isinstance(block, dict) and block.get("type") == "tool_result"
         ]
-        latest_batch = []
-        for message in reversed(messages):
-            content = message.get("content")
-            if message.get("role") != "user" or not isinstance(content, list):
-                continue
-            latest_batch = [
-                block for block in content
-                if isinstance(block, dict) and block.get("type") == "tool_result"
-            ]
-            if latest_batch:
-                break
-        latest_batch_ids = {id(block) for block in latest_batch}
-        older_results = [block for block in results if id(block) not in latest_batch_ids]
-        for block in older_results[:-self.KEEP_RECENT_RESULTS]:
+        unseen = self.unseen_tool_result_positions(messages)
+        consumed = [entry for entry in results if entry[:2] not in unseen]
+        for _, _, block in consumed[:-self.KEEP_RECENT_RESULTS]:
             content = str(block.get("content", ""))
             if len(content) <= 120:
                 continue