fix(agent): preserve core hook failure semantics

nanobot/agent/__init__.py

@@ -2,10 +2,10 @@
 
 from nanobot.agent.context import ContextBuilder
 from nanobot.agent.hook import AgentHook, AgentHookContext, CompositeHook
-from nanobot.agent.loop import AgentLoop, LoopHook
+from nanobot.agent.loop import AgentLoop
 from nanobot.agent.memory import MemoryStore
 from nanobot.agent.skills import SkillsLoader
-from nanobot.agent.subagent import SubagentHook, SubagentManager
+from nanobot.agent.subagent import SubagentManager
 
 __all__ = [
     "AgentHook",
@@ -13,9 +13,7 @@ __all__ = [
     "AgentLoop",
     "CompositeHook",
     "ContextBuilder",
-    "LoopHook",
     "MemoryStore",
     "SkillsLoader",
-    "SubagentHook",
     "SubagentManager",
 ]

nanobot/agent/loop.py

@@ -37,12 +37,11 @@ if TYPE_CHECKING:
     from nanobot.cron.service import CronService
 
 
-class LoopHook(AgentHook):
+class _LoopHook(AgentHook):
     """Core lifecycle hook for the main agent loop.
 
     Handles streaming delta relay, progress reporting, tool-call logging,
-    and think-tag stripping.  Public so downstream users can subclass or
-    compose it via :class:`CompositeHook`.
+    and think-tag stripping for the built-in agent path.
     """
 
     def __init__(
@@ -105,7 +104,7 @@ class LoopHook(AgentHook):
 class _LoopHookChain(AgentHook):
     """Run the core loop hook first, then best-effort extra hooks.
 
-    This preserves the historical failure behavior of ``LoopHook`` while still
+    This preserves the historical failure behavior of ``_LoopHook`` while still
     letting user-supplied hooks opt into ``CompositeHook`` isolation.
     """
 
@@ -325,7 +324,7 @@ class AgentLoop:
         ``resuming=True`` means tool calls follow (spinner should restart);
         ``resuming=False`` means this is the final response.
         """
-        loop_hook = LoopHook(
+        loop_hook = _LoopHook(
             self,
             on_progress=on_progress,
             on_stream=on_stream,

nanobot/agent/subagent.py

@@ -21,11 +21,8 @@ from nanobot.config.schema import ExecToolConfig
 from nanobot.providers.base import LLMProvider
 
 
-class SubagentHook(AgentHook):
-    """Logging-only hook for subagent execution.
-
-    Public so downstream users can subclass or compose via :class:`CompositeHook`.
-    """
+class _SubagentHook(AgentHook):
+    """Logging-only hook for subagent execution."""
 
     def __init__(self, task_id: str) -> None:
         self._task_id = task_id
@@ -138,7 +135,7 @@ class SubagentManager:
                 tools=tools,
                 model=self.model,
                 max_iterations=15,
-                hook=SubagentHook(task_id),
+                hook=_SubagentHook(task_id),
                 max_iterations_message="Task completed but no final response was generated.",
                 error_message=None,
                 fail_on_tool_error=True,