idea: Add option in Appearance Settings to toggle between frameless and native app shell for Window & Ubuntu users

[imtuyethan]

Problem Statement

Jan's custom window decorations (since v0.5.1) cause issues on Linux & Windows, especially with less common themes or window managers. The app feels unnatural, lacks proper integration (no shadows, non-native right-click menus), and is harder to use (difficult menubar access). This disrupts workflow for Linux & Windows users though most people prefer the simplicity of 0.5.3 app shell.

Feature Idea

Add a "Use Native Window Decorations" toggle in Appearance Settings. When enabled, it will use the system's native window decorations.

Related issue: #3093