fix(config): retire max messages setting

tests/agent/test_max_messages_config.py

@@ -1,4 +1,4 @@
-"""Tests for max_messages config wiring into session history replay."""
+"""Tests for the internal max_messages replay cap."""
 
 from __future__ import annotations
 
@@ -11,9 +11,9 @@ from nanobot.agent.loop import AgentLoop
 from nanobot.bus.events import InboundMessage
 from nanobot.bus.queue import MessageBus
 from nanobot.providers.base import LLMResponse
-from nanobot.session.manager import Session
+from nanobot.session.manager import DEFAULT_REPLAY_MAX_MESSAGES, Session
 
-DEFAULT_MAX_MESSAGES = 500
+DEFAULT_MAX_MESSAGES = DEFAULT_REPLAY_MAX_MESSAGES
 
 
 def _make_loop(tmp_path: Path, max_messages: int = DEFAULT_MAX_MESSAGES) -> AgentLoop:
@@ -103,10 +103,10 @@ class TestGetHistoryWithMaxMessages:
 
 
 class TestMaxMessagesIntegration:
-    """Verify the config flows from AgentLoop into get_history calls."""
+    """Verify AgentLoop passes the replay cap into get_history calls."""
 
     @pytest.mark.asyncio
-    async def test_process_message_passes_config_to_history_call(self, tmp_path: Path) -> None:
+    async def test_process_message_passes_limit_to_history_call(self, tmp_path: Path) -> None:
         """The real message path should pass max_messages into session history replay."""
         loop = _make_loop(tmp_path, max_messages=25)
         loop.provider.chat_with_retry = AsyncMock(
@@ -127,7 +127,7 @@ class TestMaxMessagesIntegration:
         assert mock_hist.call_args.kwargs["extend_to_user"] is False
 
     @pytest.mark.asyncio
-    async def test_zero_config_passes_builtin_limit_to_history_call(self, tmp_path: Path) -> None:
+    async def test_zero_limit_passes_builtin_limit_to_history_call(self, tmp_path: Path) -> None:
         loop = _make_loop(tmp_path, max_messages=0)
         loop.provider.chat_with_retry = AsyncMock(
             return_value=LLMResponse(content="ok", tool_calls=[], usage={})
@@ -182,31 +182,3 @@ class TestMaxMessagesIntegration:
         sent_text = "\n".join(str(message.get("content")) for message in sent_messages)
         assert "new question" in sent_text
         assert "long older turn" not in sent_text
-
-
-class TestSchemaConfig:
-    """Verify the config schema accepts max_messages."""
-
-    def test_schema_default(self) -> None:
-        from nanobot.config.schema import AgentDefaults
-
-        defaults = AgentDefaults()
-        assert defaults.max_messages == DEFAULT_MAX_MESSAGES
-
-    def test_schema_accepts_zero_as_builtin_limit(self) -> None:
-        from nanobot.config.schema import AgentDefaults
-
-        defaults = AgentDefaults(max_messages=0)
-        assert defaults.max_messages == 0
-
-    def test_schema_accepts_positive(self) -> None:
-        from nanobot.config.schema import AgentDefaults
-
-        defaults = AgentDefaults(max_messages=25)
-        assert defaults.max_messages == 25
-
-    def test_schema_rejects_negative(self) -> None:
-        from nanobot.config.schema import AgentDefaults
-
-        with pytest.raises(Exception):  # Pydantic validation error
-            AgentDefaults(max_messages=-1)

tests/config/test_config_migration.py

@@ -2,6 +2,8 @@ import json
 import socket
 from unittest.mock import patch
 
+import pytest
+
 from nanobot.config.loader import load_config, save_config
 from nanobot.security.network import validate_url_target
 
@@ -93,6 +95,41 @@ def test_onboard_does_not_crash_with_legacy_memory_window(tmp_path, monkeypatch)
     assert result.exit_code == 0
 
 
+@pytest.mark.parametrize("field_name", ["maxMessages", "max_messages"])
+def test_load_config_warns_and_ignores_legacy_max_messages(tmp_path, field_name) -> None:
+    config_path = tmp_path / "config.json"
+    config_path.write_text(
+        json.dumps({"agents": {"defaults": {field_name: 25, "maxTokens": 1234}}}),
+        encoding="utf-8",
+    )
+
+    with patch("nanobot.config.loader.logger.warning") as warning:
+        config = load_config(config_path)
+
+    assert config.agents.defaults.max_tokens == 1234
+    assert not hasattr(config.agents.defaults, "max_messages")
+    warning.assert_called_once()
+    message = warning.call_args.args[0]
+    assert "legacy and ignored" in message
+    assert "next version" in message
+
+
+def test_save_config_drops_legacy_max_messages(tmp_path) -> None:
+    config_path = tmp_path / "config.json"
+    config_path.write_text(
+        json.dumps({"agents": {"defaults": {"maxMessages": 25}}}),
+        encoding="utf-8",
+    )
+
+    with patch("nanobot.config.loader.logger.warning"):
+        config = load_config(config_path)
+    save_config(config, config_path)
+    saved = json.loads(config_path.read_text(encoding="utf-8"))
+
+    assert "maxMessages" not in saved["agents"]["defaults"]
+    assert "max_messages" not in saved["agents"]["defaults"]
+
+
 def test_onboard_refresh_backfills_missing_channel_fields(tmp_path, monkeypatch) -> None:
     from types import SimpleNamespace