[Scenario] The image shows a maze with black walls and white paths. The green circle is the agent's starting position. Multiple coloured diamonds mark keys (each a different colour) and a single coloured hollow square marks the door.
[Rules]
1. The agent must collect EVERY key (the key disappears the moment it is picked up).
2. After collecting all keys, the agent must walk to the door cell.
3. The agent may only move along white path cells; it cannot cross black walls.
4. Pick the key-collection order that minimises the total travel distance (agent → first key → … → last key → door).
[Task] The agent collects all keys (in the optimal order) and then reaches the door. The camera is fixed; the maze layout does not change. Only modify what the task requires; keep the background and any other element unchanged. Output one image after each key is collected and one after reaching the door, with each path segment drawn as a yellow line.