Avatar character renders as box/question mark in PowerShell 7 on Windows

Description

The Claude Code avatar/icon displays as a box with a question mark (□?) in PowerShell 7 (pwsh) running in a standalone conhost window on Windows 11.

Environment

• OS: Windows 11 Pro
• Terminal: PowerShell 7 (pwsh) in conhost (not Windows Terminal)
• Claude Code version: latest

Steps to Reproduce

1. Open PowerShell 7 directly (not via Windows Terminal)
2. Launch Claude Code
3. Observe the avatar/icon in the UI

Expected Behavior

The Claude Code avatar/icon renders correctly.

Actual Behavior

The avatar/icon displays as a box with a question mark, indicating the Unicode character used cannot be rendered by the conhost font.

Workaround

Running PowerShell 7 inside Windows Terminal (with Cascadia Code font) renders the character correctly.