config: add drag-handle

src/config/Config.zig

@@ -2345,6 +2345,30 @@ keybind: Keybinds = .{},
 /// Specified as either hex (`#RRGGBB` or `RRGGBB`) or a named X11 color.
 @"window-titlebar-foreground": ?Color = null,
 
+/// Controls when drag handles are shown over splits,
+/// allowing splits to be rearranged with mouse controls.
+///
+/// Valid values:
+///
+///  - `always`
+///
+///    Always display the drag handle, even when there's only one split.
+///
+///  - `auto` *(default)*
+///
+///    Automatically show and hide the drag handle. The handle is only
+///    shown when there are two or more splits present.
+///
+///  - `never`
+///
+///    Never show the drag handle. Splits then cannot be rearranged with
+///    mouse controls.
+///
+/// Available since: 1.4.0.
+///
+/// Currently only supported on Linux (GTK).
+@"drag-handle": DragHandle = .auto,
+
 /// This controls when resize overlays are shown. Resize overlays are a
 /// transient popup that shows the size of the terminal while the surfaces are
 /// being resized. The possible options are:
@@ -9297,6 +9321,13 @@ pub const WindowShowTabBar = enum {
     never,
 };
 
+/// See drag-handle
+pub const DragHandle = enum {
+    always,
+    auto,
+    never,
+};
+
 /// See resize-overlay
 pub const ResizeOverlay = enum {
     always,