fix(session): stop training the model to parrot [Message Time: ...]

Past assistant turns in history were prefixed with "[Message Time: ...]"
just like user turns. The model treated these as in-context demos and
started prefixing its own replies with the same marker, leaking
metadata to the user. Prompt-level warnings could not beat dozens of
prior assistant samples.

Annotate only user turns and proactive deliveries
(_channel_delivery=True, i.e. cron / heartbeat pushes whose timing is
the whole point and which are too infrequent to act as demos). Adjacent
user-side timestamps still pin every normal assistant reply for
relative-time reasoning. The now-redundant identity.md warning is
removed along with the demonstration source.

nanobot/session/manager.py

@@ -32,13 +32,27 @@ class Session:
 
     @staticmethod
     def _annotate_message_time(message: dict[str, Any], content: Any) -> Any:
-        """Expose persisted turn timestamps to the model for relative-date reasoning."""
+        """Expose persisted turn timestamps to the model for relative-date reasoning.
+
+        Annotating *every* assistant turn trains the model (via in-context
+        demonstrations) to start its own replies with the same
+        ``[Message Time: ...]`` prefix, which leaks metadata back to the user.
+        We therefore only annotate:
+
+        * ``user`` turns — needed so the model can pin the conversation in time.
+        * proactive deliveries (``_channel_delivery=True``) — cron / heartbeat
+          assistant pushes that may sit hours away from the next user reply,
+          and are too infrequent to act as parroting demonstrations.
+        """
         timestamp = message.get("timestamp")
-        if (
-            not timestamp
-            or message.get("role") not in {"user", "assistant"}
-            or not isinstance(content, str)
-        ):
+        if not timestamp or not isinstance(content, str):
+            return content
+        role = message.get("role")
+        if role == "user":
+            pass
+        elif role == "assistant" and message.get("_channel_delivery"):
+            pass
+        else:
             return content
         return f"[Message Time: {timestamp}]\n{content}"
 

nanobot/templates/agent/identity.md

@@ -28,9 +28,5 @@ Output is rendered in a terminal. Avoid markdown headings and tables. Use plain
 - On broad searches, use `grep(output_mode="count")` to scope before requesting full content.
 {% include 'agent/_snippets/untrusted_content.md' %}
 
-Historical messages may include `[Message Time: ...]` prefixes. Treat them as
-metadata for chronology only; never quote, copy, or include those markers in
-your response.
-
 Reply directly with text for conversations. Only use the 'message' tool to send to a specific chat channel.
 IMPORTANT: To send files (images, video, audio, documents) to the user, you MUST call the 'message' tool with the 'media' parameter. Do NOT use read_file to "send" a file — reading a file only shows its content to you, it does NOT deliver the file to the user. Examples: message(content="Here is the image", media=["/path/to/file.png"]) or message(content="Here is the video", media=["/path/to/video.mp4"])