/export command reports success but writes empty content

Description

The /export command reports success but doesn't actually write any content — both clipboard and file exports are empty.

Steps to reproduce

1. Have an active conversation with some history
2. Run /export (clipboard mode) — reports "Conversation copied to clipboard", but pbpaste returns empty
3. Run /export somefile (file mode) — reports "Conversation exported to: .../somefile.txt", but the file is 0 bytes

Expected behavior

Clipboard / file should contain the conversation transcript.

Actual behavior

• /export → "Conversation copied to clipboard" but clipboard is empty (verified with pbpaste | wc -c → 0)
• /export somefile → creates the file but it's 0 bytes (verified with wc -l and ls -la)

Environment

• macOS (Darwin 25.2.0)
• Claude Code CLI
• Model: claude-opus-4-6