Memories are leaking between repositories

### Describe the bug

Today I have had a strange situation. I created a new git repository, checked it out and then asked copilot to add some basic instructions and project setup.

Out of the nowhere, it mumbled about some "facts stored in the memory" (of course there are none because the repo is fresh!) that seem to be part of a different (similar named) repository...

### Affected version

_No response_

### Steps to reproduce the behavior

_No response_

### Expected behavior

_No response_

### Additional context

_No response_

首先，使用一個名稱類似於另一個 repository 的全新 repository 重現該報告，然後追蹤 Copilot CLI 在哪裡讀取儲存的記憶並將其與 repository 關聯。當一個 repository 中的記憶無法出現在另一個 repository 中，且該行為由回歸測試涵蓋時，此 issue 即完成。

由索引模型根據 Issue 內容生成。