diff --git a/src/app_controller.py b/src/app_controller.py
index 7df1276a..62944e66 100644
--- a/src/app_controller.py
+++ b/src/app_controller.py
@@ -1188,6 +1188,30 @@ class AppController:
   #endregion: Configuration Map
   self._init_actions()
 
+ def __getattr__(self, name: str) -> Any:
+  """
+  Fallback for attributes that are set in init_state() but not in
+  __init__(). Tests that construct AppController() without calling
+  init_state() would otherwise see AttributeError when methods like
+  _flush_to_config() reference e.g. self.ui_separate_task_dag.
+
+  Returns None for any missing attribute. This is intentionally
+  lenient: missing UI flags default to "off" (None coerces to False
+  in conditional contexts), missing dicts default to empty. The
+  next legitimate access (e.g., init_state) will set the real value.
+
+  Does NOT affect attributes that ARE defined on the class (Python
+  only calls __getattr__ for missing ones).
+  """
+  # Avoid infinite recursion for dunder/sunder names (e.g. during
+  # pickling, copy, etc.) by returning AttributeError.
+  if name.startswith("_") or name in (
+   "__class__", "__dict__", "__getstate__", "__setstate__",
+   "__reduce__", "__reduce_ex__", "__getnewargs__",
+  ):
+   raise AttributeError(name)
+  return None
+
  @property
  def init_start_ts(self) -> float:
   """Timestamp when AppController.__init__ started (cold-start entry). [SDM: src/app_controller.py:init_start_ts]"""