feat: preserve planner context across task steps

runtime/context.py

@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 from dataclasses import dataclass, field
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, Any
 
 from core.models import Scene
 
@@ -18,6 +18,7 @@ class TaskContext:
     scenes: list[Scene] = field(default_factory=list)
     step_results: list["StepResult"] = field(default_factory=list)
     world: "WorldState | None" = None
+    planner_history: list[dict[str, Any]] = field(default_factory=list)
 
     def add_scene(self, scene: Scene) -> None:
         self.scenes.append(scene)