Primitives · raise: what opens inside a dialog lies over it

gpui 0.2.2 asserts on a deferred draw inside another, and every dialog,
sheet and popover draws inside one, so opening a date field in the
snooze or schedule dialog panicked, as would any list, menu or picker
opened in an overlay. primitives::raise replaces each deferred draw:
at the top it defers as before; inside something raised it leaves a
placeholder in the tree, and its layer lays it out on its own, then
draws it last. check.sh refuses gpui's deferred anywhere else.

The time dialog's rule is now times::ahead, tested for a moment
behind, now itself, a moment ahead and another zone; a gpui test picks
yesterday in the snooze dialog, sees that it has passed and that
nothing is sent, then picks two days ahead and hears that moment.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/primitives/backdrop.rs

@@ -2,11 +2,11 @@ use std::rc::Rc;
 
 use gpui::{
     Animation, AnimationExt, AnyElement, App, ElementId, InteractiveElement, IntoElement,
-    MouseButton, ParentElement, Point, RenderOnce, Styled, Window, anchored, deferred, div,
-    prelude::*,
+    MouseButton, ParentElement, Point, RenderOnce, Styled, Window, anchored, div, prelude::*,
 };
 use smallvec::SmallVec;
 
+use super::raise;
 use crate::{motion, theme::ActiveTheme};
 
 type Dismiss = Rc<dyn Fn(&mut Window, &mut App)>;
@@ -81,7 +81,7 @@ impl RenderOnce for Backdrop {
                 |scrim, t| scrim.opacity(t),
             );
 
-        deferred(
+        raise(
             anchored().position(Point::default()).child(
                 div()
                     .relative()