quick terminal: GHOSTTY_QUICK_TERMINAL is not set in new split

[imroc]

Issue Description

When use quick terminal, GHOSTTY_QUICK_TERMINAL will be set to 1, but not set in new split

Expected Behavior

GHOSTTY_QUICK_TERMINAL should always be set in quick terminal (every pane)

Actual Behavior

GHOSTTY_QUICK_TERMINAL is only set in first pane in quick terminal.

Reproduction Steps

1. Open quick terminal
2. Press Cmd+D to create new split
3. Check env: env | grep GHOSTTY_QUICK_TERMINAL

Ghostty Logs

No response

Ghostty Version

Ghostty 1.3.1

Version
  - version: 1.3.1
  - channel: stable
Build Config
  - Zig version   : 0.15.2
  - build mode    : .ReleaseFast
  - app runtime   : .none
  - font engine   : .coretext
  - renderer      : renderer.generic.Renderer(renderer.Metal)
  - libxev        : kqueue

OS Version Information

MacOS 26.4.1 (25E253)

(Linux only) Display Server

None

(Linux only) Desktop Environment/Window Manager

No response

Minimal Ghostty Configuration

keybind = global:cmd+/=toggle_quick_terminal

Additional Relevant Configuration

No response

I acknowledge that:

• I have reviewed the FAQ and confirm that my issue is NOT among them.
• I have searched the Ghostty repository (both open and closed Discussions and Issues) and confirm this is not a duplicate of an existing issue or discussion.
• I have checked the "Preview" tab on all text fields to ensure that everything looks right, and have wrapped all configuration and code in code blocks with a group of three backticks (```) on separate lines.

[52dyd]

Same root cause as #11637 — macOS-specific: env_vars is set per-surface rather than per-window. I've opened a vouch request with a fix at #12840.