Windows: Edit in Source Mode immediately switches back to visual if header says `editor: visual`

Bug description

System details:

Positron and OS details:

Positron Version: 2026.05.2 (user setup) build 3
Code - OSS Version: 1.109.2
Commit: 1b5dfba9314510340cb08f2fedccc5ffba822beb
Date: 2026-05-13T19:16:42.268Z
Electron: 39.3.0
Chromium: 142.0.7444.265
Node.js: 22.21.1
V8: 14.2.231.22-electron.0
OS: Windows_NT x64 10.0.26200

Describe the issue:

My qmd has

---
title: "Vehicle In Operation + Demographics Data (VIOD/Experian) preprocessing for TEMPO model inputs"
author: "arthuryip"
format: html
editor: visual
---

at the top.

When I click the menu ... button "Edit in Source mode", it tries to switch to source mode, but then immediately goes back to visual mode.

Expected or desired behavior:

go to source mode because i clicked edit in source mode. override header setting.

Also,
after i change the header to say editor: source, then clicking Edit in Source Mode works.

Steps to reproduce

No response

Actual behavior

No response

Expected behavior

No response

Your environment

No response

Reproduce on Windows with a QMD file whose YAML header sets editor: visual, then use the menu's “Edit in Source Mode” command and compare it with a header set to editor: source. Trace the source-mode command and its editor-setting handling; done means the explicit command remains in source mode despite the header setting, without breaking normal visual-mode selection.