/telegram - Toggle Telegram Approval Mode

When the user invokes /telegram, do the following:

Behavior

Without arguments (/telegram)

1. Check current status
2. Toggle: if ON -> turn OFF, if OFF -> turn ON
3. Confirm with one short line

With arguments (/telegram on, /telegram off)

Execute directly without menu.

Implementation

The Telegram mode is controlled by a flag file at /tmp/claude_telegram_active.