Constant TITLEBAR_H 

pub const TITLEBAR_H: f32 = _ /* 34f32 */;

Default titlebar height, logical px, where the strip is the app’s alone. Follows platform conventions (as measured by gpui): 32 on Windows (the native caption height), 34 elsewhere. The stock Metrics carries the same number as titlebar_h, and the titlebar draws from that, so an app that set its own metrics lays out against ui.metrics().titlebar_h rather than this constant — and where the OS keeps controls of its own over the strip, against titlebar_height.