fix(agent): persist shortcut commands without polluting LLM context

Shortcut commands (e.g. /help, /pairing) skip BUILD and SAVE states,
so their turns were never persisted to the session.  This caused WebUI
chats to appear empty after _turn_end because history hydration reads
from the session file.

Fix by persisting the user message and assistant response inside
_state_command, but tag them with _command=True so Session.get_history
filters them out of LLM context.  /new is excluded because it
intentionally clears the session.

- AgentLoop._persist_user_message_early now accepts **kwargs so
  _state_command can pass _command=True for the user turn.
- Session.get_history skips messages with _command=True.

nanobot/agent/loop.py

@@ -564,6 +564,7 @@ class AgentLoop:
         self,
         msg: InboundMessage,
         session: Session,
+        **kwargs: Any,
     ) -> bool:
         """Persist the triggering user message before the turn starts.
 
@@ -573,6 +574,7 @@ class AgentLoop:
         has_text = isinstance(msg.content, str) and msg.content.strip()
         if has_text or media_paths:
             extra: dict[str, Any] = {"media": list(media_paths)} if media_paths else {}
+            extra.update(kwargs)
             text = msg.content if isinstance(msg.content, str) else ""
             session.add_message("user", text, **extra)
             self._mark_pending_user_turn(session)
@@ -1268,6 +1270,19 @@ class AgentLoop:
         result = await self.commands.dispatch(cmd_ctx)
         if result is not None:
             ctx.outbound = result
+            # Shortcut commands skip BUILD and SAVE, so we must persist the
+            # turn here so WebUI history hydration after _turn_end sees the
+            # message.  Mark messages with _command so get_history can filter
+            # them out of LLM context.  /new is excluded because it
+            # intentionally clears the session.
+            if raw.lower() != "/new":
+                ctx.user_persisted_early = self._persist_user_message_early(
+                    ctx.msg, ctx.session, _command=True
+                )
+                ctx.session.add_message(
+                    "assistant", result.content, _command=True
+                )
+                self.sessions.save(ctx.session)
             return "shortcut"
         return "dispatch"
 

nanobot/session/manager.py

@@ -139,6 +139,8 @@ class Session:
 
         out: list[dict[str, Any]] = []
         for message in sliced:
+            if message.get("_command"):
+                continue
             content = message.get("content", "")
             role = message.get("role")
             if role == "assistant" and isinstance(content, str):

tests/agent/test_auto_compact.py

@@ -418,6 +418,40 @@ class TestAutoCompactIdleDetection:
         assert len(session_after.messages) == 0
         await loop.close_mcp()
 
+    @pytest.mark.asyncio
+    async def test_shortcut_command_persisted_with_command_flag(self, tmp_path):
+        """Shortcut commands (e.g. /help) are persisted so WebUI can show them,
+        but tagged with _command so they don't leak into LLM context."""
+        loop = _make_loop(tmp_path)
+        msg = InboundMessage(channel="cli", sender_id="user", chat_id="test", content="/help")
+        response = await loop._process_message(msg)
+
+        assert response is not None
+        session_after = loop.sessions.get_or_create("cli:test")
+        assert len(session_after.messages) == 2
+        assert session_after.messages[0]["role"] == "user"
+        assert session_after.messages[0]["content"] == "/help"
+        assert session_after.messages[0].get("_command") is True
+        assert session_after.messages[1]["role"] == "assistant"
+        assert session_after.messages[1].get("_command") is True
+        await loop.close_mcp()
+
+    @pytest.mark.asyncio
+    async def test_shortcut_command_excluded_from_get_history(self, tmp_path):
+        """Messages marked _command are invisible to get_history (LLM context)."""
+        loop = _make_loop(tmp_path)
+        session = loop.sessions.get_or_create("cli:test")
+        session.add_message("user", "real question")
+        session.add_message("assistant", "real answer")
+        session.add_message("user", "/help", _command=True)
+        session.add_message("assistant", "help text", _command=True)
+
+        history = session.get_history()
+        assert len(history) == 2
+        assert all(m["content"] != "/help" for m in history)
+        assert all(m["content"] != "help text" for m in history)
+        await loop.close_mcp()
+
 
 class TestAutoCompactSystemMessages:
     """Test that auto-new also works for system messages."""