Move workspace popover to window root + dismiss on outside click

Previously the disclosure was an absolute child of the picker row,
clipped by the sidebar's overflow_hidden, with no way for an outside
click to close it. Real popovers (Arc, Linear, Raycast) close the
moment you click anywhere else, and they spill past their host
container so a long workspace list isn't cut at the sidebar edge.

Lift the disclosure to the render_browser tree:

* `render_workspace_disclosure_backdrop` paints a fullscreen
  transparent layer that closes the picker on mouse-down — no
  on_click so the close fires immediately, before any synthetic click.
* `render_workspace_disclosure` paints next, pinned to fixed
  window-relative anchor coords (top 98, left 66, width 180) that
  match the picker pill's row in the default sidebar layout.

The picker row inside the sidebar header drops the inline disclosure
child entirely.

cargo test --workspace: 440 passed, 0 failed.

crates/ely_app/src/shell/chrome/mod.rs

@@ -24,7 +24,9 @@ pub(crate) use home::render_home_page;
 pub(crate) use plugin_detail_view::render_plugin_detail_view;
 pub(crate) use settings_layout::render_settings_landing;
 pub(crate) use sidebar::{panel_bg, panel_shadow};
-pub(crate) use sidebar_header::render_sidebar_header;
+pub(crate) use sidebar_header::{
+    render_sidebar_header, render_workspace_disclosure, render_workspace_disclosure_backdrop,
+};
 pub(crate) use split_pane::{
     pane_host_label, pane_url_is_secure, render_compact_split_canvas,
     render_split_pane_header,

crates/ely_app/src/shell/chrome/sidebar_header.rs

@@ -69,13 +69,16 @@ fn render_title_row() -> AnyElement {
 const TRAFFIC_LIGHT_RESERVE: f32 = 68.0;
 
 fn render_workspace_picker(
-    snapshot: &BrowserSnapshot,
+    _snapshot: &BrowserSnapshot,
     active_space: Option<&Space>,
     picker_open: bool,
     cx: &mut Context<ElyShell>,
 ) -> AnyElement {
+    // The disclosure renders at the window root (see render.rs) so it can
+    // sit above a fullscreen click-out backdrop and extend past the
+    // sidebar's overflow_hidden clip. Picker row keeps just the tile, the
+    // pill, and the add button.
     div()
-        .relative()
         .flex()
         .items_center()
         .gap(px(6.0))
@@ -84,12 +87,6 @@ fn render_workspace_picker(
         .child(render_workspaces_tile(cx))
         .child(render_picker_pill(active_space, picker_open, cx))
         .child(render_add_workspace_button(cx))
-        // Disclosure floats below the picker row instead of taking inline
-        // space so the tab list never gets pushed when a workspace is being
-        // picked. Anchor: picker row's bottom-left, full row width.
-        .when(picker_open, |el| {
-            el.child(render_workspace_disclosure(snapshot, cx))
-        })
         .into_any_element()
 }
 
@@ -173,7 +170,12 @@ fn render_picker_pill(
         .into_any_element()
 }
 
-fn render_workspace_disclosure(
+/// Window-root popover surface for the workspace picker. Rendered by
+/// render_browser when `workspace_picker_open` is true. Pinned to a
+/// fixed window-relative origin matched to the picker pill's row in
+/// the sidebar header, so the surface lines up with the trigger
+/// without needing to capture bounds at paint time.
+pub(crate) fn render_workspace_disclosure(
     snapshot: &BrowserSnapshot,
     cx: &mut Context<ElyShell>,
 ) -> AnyElement {
@@ -181,10 +183,9 @@ fn render_workspace_disclosure(
 
     let body = div()
         .absolute()
-        .top_full()
-        .left_0()
-        .right_0()
-        .mt(px(6.0))
+        .top(px(DISCLOSURE_TOP_PX))
+        .left(px(DISCLOSURE_LEFT_PX))
+        .w(px(DISCLOSURE_WIDTH_PX))
         .flex()
         .flex_col()
         .gap(px(2.0))
@@ -208,6 +209,43 @@ fn render_workspace_disclosure(
     fade_in("workspace-disclosure", 140, body).into_any_element()
 }
 
+/// Transparent fullscreen backdrop layered between the layout grid
+/// and the disclosure. Any click on it closes the picker; the
+/// disclosure paints after this backdrop so it remains interactive.
+pub(crate) fn render_workspace_disclosure_backdrop(
+    cx: &mut Context<ElyShell>,
+) -> AnyElement {
+    div()
+        .id(SharedString::from("workspace-picker-backdrop"))
+        .absolute()
+        .inset_0()
+        .on_mouse_down(
+            gpui::MouseButton::Left,
+            cx.listener(|shell, _: &gpui::MouseDownEvent, _, cx| {
+                shell.close_workspace_picker(cx);
+            }),
+        )
+        .into_any_element()
+}
+
+/// Anchor of the disclosure popover relative to the window's top-left.
+/// Walks the sidebar layout: SHELL_INSET (16) + sidebar header pt (8)
+/// + title row h (20) + header gap (8) + picker row py-top (4) + tile
+/// height (32) + picker row py-bot (4) + popover lift (6) = 98.
+const DISCLOSURE_TOP_PX: f32 = 98.0;
+
+/// Left edge of the disclosure: SHELL_INSET (16) + header px-left (10)
+/// + picker row px-left (2) + tile width (32) + picker gap (6) = 66.
+/// That lines the disclosure up with the picker pill, not the tile.
+const DISCLOSURE_LEFT_PX: f32 = 66.0;
+
+/// Default sidebar (280 px) → pill width 180 px. The disclosure inherits
+/// that width so the popover and trigger frame to the same column. If
+/// the sidebar is resized the disclosure stays a fixed width — picker
+/// is closed before the user can drag, so the misalignment is
+/// transient at worst.
+const DISCLOSURE_WIDTH_PX: f32 = 180.0;
+
 fn render_disclosure_row(
     index: usize,
     space: &Space,

crates/ely_app/src/shell/render.rs

@@ -10,7 +10,8 @@ use gpui::{
 use super::chrome::command_match::visible_command_rows;
 use super::chrome::{
     SANS_FAMILY, panel_bg, panel_shadow, render_command_overlay,
-    render_topbar as render_topbar_chrome, render_wallpaper,
+    render_topbar as render_topbar_chrome, render_wallpaper, render_workspace_disclosure,
+    render_workspace_disclosure_backdrop,
 };
 use super::sidebar::collapsed_sidebar_active;
 use super::{ElyShell, ShellState};
@@ -92,6 +93,10 @@ impl ElyShell {
             .when(hover_expanded, |el| {
                 el.child(self.render_hidden_sidebar_overlay(&snapshot, cx))
             })
+            .when(self.workspace_picker_open, |el| {
+                el.child(render_workspace_disclosure_backdrop(cx))
+                    .child(render_workspace_disclosure(&snapshot, cx))
+            })
             .children(render_command_overlay(self, &snapshot, cx))
             .into_any_element()
     }