fix(ui): centre the title bar search over the terminal column off macOS

With a document or the detail panel docked, the title bar spans the
workspace on Windows and Linux, and the Search Everywhere box centred on
all of it landed under the document's hoisted header, which has no fill
to hide it.

src/ui/tab_strip.rs

@@ -2461,6 +2461,26 @@ impl Tty7App {
         // that opens the search where it stands. The rail beside it already
         // names every tab, so the bar has no title of its own to repeat. The
         // box alone takes the pointer; the rest of the bar still drags.
+        //
+        // Centred over the terminal column, not the bar. Off macOS the bar
+        // spans the workspace while a document or the detail panel is docked,
+        // and centred on all of it the box landed under the document's
+        // hoisted header, which has no fill to hide it. The strip already
+        // stops short of the window controls, so they come off the columns'
+        // share.
+        let search_right = match cfg!(target_os = "macos") {
+            true => 0.,
+            false => {
+                let panel = match self.right_panel_open(cx) {
+                    true => self.right_panel_px(window, cx),
+                    false => 0.,
+                };
+                match panel + document_w > 0. {
+                    true => (panel + document_w - controls_w).max(0.),
+                    false => 0.,
+                }
+            }
+        };
         let centre_search = (!show_chips).then(|| {
             // The chord as text, not caps: a cap's fill is this box's own
             // grey, so on it a cap is only a gap between two letters.
@@ -2468,7 +2488,10 @@ impl Tty7App {
                 .map(|spec| crate::ui::keymap::key_tokens(&spec).join(""));
             div()
                 .absolute()
-                .inset_0()
+                .top_0()
+                .bottom_0()
+                .left_0()
+                .right(px(search_right))
                 .flex()
                 .items_center()
                 .justify_center()