Undocumented `logs/security/.security-key` file created in every working directory on startup

Description

Copilot CLI creates a logs/security/.security-key file in the current working directory as soon as a session starts. This happens in every directory, including a brand-new empty one, so it appears to be unconditional CLI startup behavior rather than something tied to a specific repo or project config.

I can't find this documented anywhere - not in the CLI config-directory reference, the command reference, or recent changelogs (checked back through v1.0.76). Filing this to understand what the file is for and whether it's expected to live in the project directory rather than ~/.copilot/.

Steps to reproduce

mkdir /tmp/test-copilot && cd /tmp/test-copilot && copilot
# exit the session
ls -la logs/security/

Observed

harshit@Harshits-MacBook-Pro /tmp/test-copilot » ls -la logs/security
total 8
drwxr-xr-x@ 3 harshit  wheel  96 Jul 31 10:52 .
drwxr-xr-x@ 3 harshit  wheel  96 Jul 31 10:52 ..
-rw-------@ 1 harshit  wheel  32 Jul 31 10:52 .security-key

The file contains 32 bytes of what appears to be binary/random data (confirmed via xxd), not human-readable text.

Questions

1. What is this file used for (e.g., local encryption of session state, sandbox integrity verification, telemetry)?
2. Is it intentional that it's written under <cwd>/logs/security/ rather than under ~/.copilot/? This means every project directory a user runs copilot in accumulates this file, which could easily get committed to version control if not gitignored.
3. Should this path be added to a default .gitignore suggestion, or documented in the config-directory reference alongside the other ~/.copilot/ contents?

Environment

• Copilot CLI version: GitHub Copilot CLI 1.0.77
• OS: macOS 26.4 (25E246)
• Install method: I don't remember, I have been using copilot for a while now. The only change that happened is I recently updated the version.

空のディレクトリで、提供されている mkdir、cd、copilot、ls の再現手順を実行し、その後 logs/security/.security-key を作成する CLI の起動経路を追跡します。報告で言及されている CLI の設定ディレクトリのリファレンス、コマンドリファレンス、changelog を読みます。ファイルの目的と想定される配置場所が明らかになり、gitignore に関するガイダンスとともに動作が修正または文書化されていれば完了です。