add theme titlebar height and app-owned strip dragging

crates/theme/src/source/kde.rs

@@ -79,6 +79,7 @@ impl KdeScheme {
             palette: self.palette,
             control_radius: None,
             input_height: None,
+            titlebar_height: None,
             root_font_size: None,
             accessibility,
             source: SourceKind::Kde,

crates/theme/src/source/linux.rs

@@ -142,6 +142,7 @@ impl LinuxSource {
                 palette: PartialPalette::default(),
                 control_radius: None,
                 input_height: None,
+                titlebar_height: None,
                 root_font_size: None,
                 accessibility,
                 source: SourceKind::Gnome,
@@ -154,6 +155,7 @@ impl LinuxSource {
                 palette: PartialPalette::default(),
                 control_radius: None,
                 input_height: None,
+                titlebar_height: None,
                 root_font_size: None,
                 accessibility,
                 source: SourceKind::Gnome,

crates/theme/src/source/macos.rs

@@ -113,6 +113,7 @@ impl ThemeSource for MacosSource {
             palette,
             control_radius: Some(gpui::px(CONTROL_RADIUS_PTS)),
             input_height: Some(gpui::px(INPUT_HEIGHT_PTS)),
+            titlebar_height: None,
             root_font_size: Some(gpui::px(ROOT_FONT_SIZE_PTS)),
             accessibility,
             source: SourceKind::Macos,

crates/theme/src/source/omarchy.rs

@@ -62,6 +62,7 @@ impl OmarchyTheme {
             palette: self.palette,
             control_radius: None,
             input_height: None,
+            titlebar_height: None,
             root_font_size: None,
             accessibility,
             source: SourceKind::Omarchy,

crates/theme/src/source/windows.rs

@@ -16,6 +16,8 @@ use crate::system::{AccessibilityPreferences, PartialPalette, SourceKind, System
 const CONTROL_RADIUS_PX: f32 = 4.0;
 /// WinUI 11's default text-box height, in pixels at 100% scaling.
 const INPUT_HEIGHT_PX: f32 = 32.0;
+/// The window caption's height, in pixels at 100% scaling, as Win32 reports it.
+const TITLEBAR_HEIGHT_PX: f32 = 32.0;
 /// WinUI 11's default body text size, in pixels at 100% scaling.
 const ROOT_FONT_SIZE_PX: f32 = 14.0;
 
@@ -158,6 +160,7 @@ impl ThemeSource for WindowsSource {
             },
             control_radius: Some(gpui::px(CONTROL_RADIUS_PX)),
             input_height: Some(gpui::px(INPUT_HEIGHT_PX)),
+            titlebar_height: Some(gpui::px(TITLEBAR_HEIGHT_PX)),
             root_font_size: Some(gpui::px(ROOT_FONT_SIZE_PX * text_scale as f32)),
             accessibility: self.accessibility(),
             source: SourceKind::Windows,