fix: preserve reasoning_content and thinking_blocks in session history

nanobot/agent/context.py

@@ -150,6 +150,7 @@ Reply directly with text for conversations. Only use the 'message' tool to send
         content: str | None,
         tool_calls: list[dict[str, Any]] | None = None,
         reasoning_content: str | None = None,
+        thinking_blocks: list[dict] | None = None,
     ) -> list[dict[str, Any]]:
         """Add an assistant message to the message list."""
         msg: dict[str, Any] = {"role": "assistant", "content": content}
@@ -157,5 +158,7 @@ Reply directly with text for conversations. Only use the 'message' tool to send
             msg["tool_calls"] = tool_calls
         if reasoning_content is not None:
             msg["reasoning_content"] = reasoning_content
+        if thinking_blocks:
+            msg["thinking_blocks"] = thinking_blocks
         messages.append(msg)
         return messages

nanobot/agent/loop.py

@@ -218,6 +218,7 @@ class AgentLoop:
                 messages = self.context.add_assistant_message(
                     messages, response.content, tool_call_dicts,
                     reasoning_content=response.reasoning_content,
+                    thinking_blocks=response.thinking_blocks,
                 )
 
                 for tool_call in response.tool_calls:
@@ -238,6 +239,7 @@ class AgentLoop:
                     break
                 messages = self.context.add_assistant_message(
                     messages, clean, reasoning_content=response.reasoning_content,
+                    thinking_blocks=response.thinking_blocks,
                 )
                 final_content = clean
                 break
@@ -451,7 +453,7 @@ class AgentLoop:
         """Save new-turn messages into session, truncating large tool results."""
         from datetime import datetime
         for m in messages[skip:]:
-            entry = {k: v for k, v in m.items() if k != "reasoning_content"}
+            entry = dict(m)
             role, content = entry.get("role"), entry.get("content")
             if role == "assistant" and not content and not entry.get("tool_calls"):
                 continue  # skip empty assistant messages — they poison session context