sidebar: Improve toggle button placement when fullscreen on macOS (#49524)

| Before | After |
| --- | --- |
| <img width="173" height="66" alt="grafik"
src="https://github.com/user-attachments/assets/9e406cf7-67bc-45d9-97dc-6e18515d0206"
/> | <img width="189" height="70" alt="grafik"
src="https://github.com/user-attachments/assets/b37a0c64-4130-4521-be7e-084a69c5a9c8"
/> |



Release Notes:

- N/A

crates/sidebar/src/sidebar.rs

@@ -1092,10 +1092,11 @@ impl Render for Sidebar {
                     .mt_px()
                     .pb_px()
                     .pr_1()
-                    .when(cfg!(target_os = "macos"), |this| {
-                        this.pl(px(TRAFFIC_LIGHT_PADDING))
-                    })
-                    .when(cfg!(not(target_os = "macos")), |this| this.pl_2())
+                    .when_else(
+                        cfg!(target_os = "macos") && !window.is_fullscreen(),
+                        |this| this.pl(px(TRAFFIC_LIGHT_PADDING)),
+                        |this| this.pl_2(),
+                    )
                     .justify_between()
                     .border_b_1()
                     .border_color(cx.theme().colors().border)