fix(agent): finalize max-iteration turns without tools

nanobot/session/turn_continuation.py

@@ -70,14 +70,36 @@ def should_stream_budget_response(
     message_metadata: Mapping[str, Any] | None = None,
 ) -> bool:
     """Return whether the budget-boundary response should be sent to the user."""
-    return not _continuation_available(
-        stop_reason=stop_reason,
+    if stop_reason != "max_iterations":
+        return True
+    return should_finalize_on_max_iterations(
         pending_queue_available=pending_queue_available,
         session_metadata=session_metadata,
         message_metadata=message_metadata,
     )
 
 
+def should_finalize_on_max_iterations(
+    *,
+    pending_queue_available: bool,
+    session_metadata: Mapping[str, Any] | None,
+    message_metadata: Mapping[str, Any] | None = None,
+) -> bool:
+    """Return whether a max-iteration boundary should produce a final response.
+
+    When a sustained goal can continue internally, the current runner slice
+    should stop without spending an extra no-tools finalization call. The next
+    queued continuation slice owns the eventual user-visible response.
+    """
+    return not (
+        pending_queue_available
+        and _goal_continuation_available(
+            session_metadata,
+            message_metadata=message_metadata,
+        )
+    )
+
+
 async def maybe_continue_turn(ctx: Any) -> bool:
     """Queue an internal continuation for *ctx* when policy allows it."""
     if ctx.session is None or ctx.pending_queue is None: