MCP server 'blocked by policy'

### Describe the bug

We have a custom MCP registry which is checked when local MCP servers are configured. Although the local MCP configuration is correct and works just fine within VSCode and IntelliJ plugin, an error message 'MCP server is blocked by policy' is shown.

It is unclear what causes this. The process log mentions the following:
```
2026-06-25T11:40:36.761Z [ERROR] MCP server "io.github.sooperset/mcp-atlassian" filtered: Server "io.github.sooperset/mcp-atlassian" found in registry but local configuration does not match the registered server identity
```

### Affected version

GitHub Copilot CLI 1.0.65

### Steps to reproduce the behavior

1. Configure an MCP server in the mcp-config.json in the ~/.copilot directory or just install it from within the Copilot CLI with `/mcp add`
2. The MCP server is blocked

### Expected behavior

_No response_

### Additional context

_No response_

使用 ~/.copilot 中的 mcp-config.json 或 /mcp add 入口复现该阻止，然后检查进程日志以查找注册表身份不匹配。正确配置的本地 MCP 服务器被接受，而不是被报告为受到策略阻止，即表示完成。

由索引模型根据 Issue 内容生成。