renderer: add support for floating-titlebars (#4)

Reviewed-on: https://git.kosslan.dev/wry/jay/pulls/4

jay-config/src/lib.rs

@@ -361,6 +361,27 @@ pub fn toggle_show_titles() {
     get.set_show_titles(!get.get_show_titles());
 }
 
+/// Sets whether title bars float above window content instead of being attached.
+///
+/// When enabled, title bars are rendered on top of window content without consuming
+/// layout space. Window borders do not extend to include the title bar area.
+///
+/// The default is `false`.
+pub fn set_floating_titles(floating: bool) {
+    get!().set_floating_titles(floating)
+}
+
+/// Returns whether title bars float above window content.
+pub fn get_floating_titles() -> bool {
+    get!(false).get_floating_titles()
+}
+
+/// Toggles whether title bars float above window content.
+pub fn toggle_floating_titles() {
+    let get = get!();
+    get.set_floating_titles(!get.get_floating_titles());
+}
+
 /// Sets a callback to run when this config is unloaded.
 ///
 /// Only one callback can be set at a time. If another callback is already set, it will be