Memory tooling is unavailable in new Copilot general-chat sessions

Memory tooling is unavailable in new Copilot general-chat sessions (`1.0.71-0`, Windows). Global instructions referencing saved memories load correctly, but no memory tool is registered, so memories cannot be listed or read.

This breaks persistent memory entirely: saved constraints, preferences, and prior corrections become inaccessible, making continuity and memory-backed workflows impossible.

Expected: the memory tool is registered and can read saved memories. Actual: it is absent from the session’s capabilities. Please investigate memory-tool initialization for general chat.

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| Field | Value |
| --- | --- |
| App version | 1.0.22 |
| OS | Windows 10.0.26651 |
| Theme | GitHub |
| Path | /chat |
| Tenure | Week 3 |

在新的 Copilot general-chat 会话中，使用报告中的应用版本和 Windows 环境复现该问题，然后检查会话功能以及 memory-tool 的初始化。完成标准是 memory tool 已在 general chat 中注册，并且可以列出或读取已保存的记忆。

由索引模型根据 Issue 内容生成。