[BUG] preferredNotifChannel: none does not suppress OSC notifications in Ghostty

Description

Setting preferredNotifChannel: none in ~/.claude.json does not prevent Claude Code from sending OSC 9 desktop notifications. Notifications still appear in Ghostty.

Environment

• Claude Code version: 2.1.14
• Terminal: Ghostty 1.x
• OS: macOS
• Ghostty config: desktop-notifications = true

Steps to Reproduce

1. Set ~/.claude.json:

``json
{
"preferredNotifChannel": "none"
}
``

1. Run Claude Code in Ghostty
2. Complete a task or trigger a stop event
3. Observe: "Claude Code Finished" notification still appears

Expected Behavior

With preferredNotifChannel: none, no OSC 9/777 notifications should be sent to the terminal.

Actual Behavior

Notifications still appear via Ghostty's OSC handling.

Workaround

Disable desktop-notifications in Ghostty config, but this also disables notifications from other apps.