refactor(agent-runner): tighten protocol v1 runtime boundaries

src/langbot/pkg/pipeline/msgtrun/round_policy.py

@@ -0,0 +1,34 @@
+"""Shared max-round message window helpers for Pipeline behavior."""
+from __future__ import annotations
+
+import typing
+
+
+DEFAULT_MAX_ROUND = 10
+
+
+def get_max_round(config: dict[str, typing.Any]) -> typing.Any:
+    """Return the configured Pipeline max-round value."""
+    return config.get('max-round', DEFAULT_MAX_ROUND)
+
+
+def select_max_round_messages(
+    messages: list[typing.Any] | None,
+    max_round: typing.Any,
+) -> list[typing.Any]:
+    """Select a bounded recent message window by user-round count."""
+    if not messages:
+        return []
+
+    temp_messages: list[typing.Any] = []
+    current_round = 0
+
+    for msg in messages[::-1]:
+        if current_round < max_round:
+            temp_messages.append(msg)
+            if getattr(msg, 'role', None) == 'user':
+                current_round += 1
+        else:
+            break
+
+    return temp_messages[::-1]

src/langbot/pkg/pipeline/msgtrun/truncators/round.py

@@ -3,7 +3,7 @@ from __future__ import annotations
 from .. import truncator
 import langbot_plugin.api.entities.builtin.pipeline.query as pipeline_query
 from ....agent.runner.config_migration import ConfigMigration
-from ....agent.runner.context_packager import (
+from ..round_policy import (
     get_max_round,
     select_max_round_messages,
 )