C:/Program Files/Git/copy command corrupts UTF-8 characters on Windows

Description

The /copy command in Claude Code corrupts UTF-8 characters when copying to Windows clipboard.

Environment

• OS: Windows 10/11
• Terminal: Windows Terminal / PowerShell
• Claude Code version: latest

Steps to Reproduce

1. Have Claude generate text with non-ASCII characters (e.g., Romanian diacritics: ă, ț, ș, î, â)
2. Include box-drawing characters (├, └, │, ─) in the output
3. Use /copy to copy the message
4. Paste into any text editor

Expected Behavior

Characters should be preserved exactly as displayed in the terminal.

Actual Behavior

Characters are corrupted (mojibake):

• ă → ─â
• ț → ╚Ť
• ș → ș
• ├── → ÔöťÔöÇÔöÇ
• └── → ÔööÔöÇÔöÇ

Example

Original (in terminal):

Excelentă observație
├── Item 1
└── Item 2

After /copy + paste:

Excelent─â observa╚Ťie
ÔöťÔöÇÔöÇ Item 1
ÔööÔöÇÔöÇ Item 2

Root Cause

Windows clipboard uses different encoding (CP-1252 or UTF-16) than UTF-8 used in the terminal. The /copy command likely doesn't explicitly encode as UTF-8 when writing to clipboard.

Suggested Fix

Use explicit UTF-8 encoding when copying to clipboard on Windows, possibly via pyperclip with proper encoding or Windows API with CF_UNICODETEXT format.