fix(steering): don't inject interruptions after final response

Remove the drain-after-final-response logic that forced the loop to
continue after the LLM had already finished. This caused confusing
double responses.

Correct model:
- Tool execution phase: interruption = steering (single merged response)
- Final response phase: new message = new task (separate responses)

Orphaned messages left in the checker queue after the task completes
are now re-published to the inbound bus so they're processed as
independent new tasks by the run() loop.

Made-with: Cursor

Author: xzq-xu

nanobot/agent/loop.py

@@ -417,16 +417,6 @@ def _drain_interruptions() -> str | None:
                     messages, clean, reasoning_content=response.reasoning_content,
                     thinking_blocks=response.thinking_blocks,
                 )
-
-                # Before ending, check if new messages arrived during the LLM call.
-                # If so, inject them and continue — let the model address them.
-                if injection := _drain_interruptions():
-                    messages.append({"role": "user", "content": injection})
-                    if on_progress:
-                        await on_progress(clean)
-                    logger.info("Steering: pending interruption after final response, continuing loop")
-                    continue
-
                 final_content = clean
                 break
 
@@ -559,7 +549,12 @@ async def on_stream_end(*, resuming: bool = False) -> None:
                 ))
             finally:
                 if self.enable_steering:
-                    self._interrupt_checkers.pop(msg.session_key, None)
+                    checker = self._interrupt_checkers.pop(msg.session_key, None)
+                    # Re-publish orphaned messages so they're processed as new tasks
+                    if checker:
+                        for orphan in checker.drain_all():
+                            logger.info("Steering: re-queuing orphaned message for {}", msg.session_key)
+                            await self.bus.publish_inbound(orphan)
 
     async def close_mcp(self) -> None:
         """Drain pending background archives, then close MCP connections."""