Slide the sheets and close the search view out in Firefox too

The side sheet, the bottom sheet's panel and the docked search's scrim
and view kept `display` alive through their exit with
`transition-behavior: allow-discrete`. Firefox does not transition
`display` (Chrome 117 and Safari 18 do), and `x-show` sets
`display: none` in the frame the exit starts, so in Firefox the sheets
vanished instead of sliding out and the search view and scrim vanished
instead of fading. The docked search had a second problem in every
engine: neither the view nor the scrim had a closed state to transition
to, so where `display` was held (Chrome, Safari) the view stood at full
opacity for its duration and then disappeared.

Each element now carries `x-transition:enter`/`:leave="md-transition"`,
the approach the two sheet scrims already took (renamed from
`md-scrim-transition` to one name for all of them). The class only
switches Alpine to CSS-transition mode, so `x-show` holds `display` for
the element's computed transition-duration before hiding it, in every
engine, and a reopen during the exit cancels the pending hide; nothing
styles it. `display` and `allow-discrete` leave the transitions so
Chrome and Safari do not hold a second time. Alpine reads the first
`transition-duration` listed, which is the closing slide or fade in each
list (the preset panel lists translate before height). The search view
now closes back into the bar (opacity 0, `scale: 1 0.9`, the reverse of
its `@starting-style` entry) and its scrim fades out on close and when
the search turns full screen. Under reduced motion the durations are
zero and every one of them closes at once.

Four browser tests sample each exit mid-way in the page, in the same
round trip as the close: the sheets part of the way to their closed
offset, the search scrim and view part of the way faded, each still
displayed, then `display: none`. All four fail on main in Firefox (the
two search tests in Chrome too) and pass in Chrome, Firefox and Safari.
OverlayTest pins the drawer's new transition and the view's markup.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

resources/css/components/drawer.css

@@ -18,9 +18,12 @@
  * 400px cap, 24dp start/end padding, a large corner on the inner edge only — from the specs
  * table. It enters on the emphasized-decelerate easing rather than a spring, because a sheet
  * anchored to an edge that overshot would open a gap, and leaves on emphasized accelerate: the
- * view keeps `x-show`, so `@starting-style` gives the entry its start and `allow-discrete` holds
- * `display` through the exit, whose timing comes from the closed state's own rule (a transition
- * takes the after-change style's). Reduced motion zeroes both duration tokens (tokens/motion.css).
+ * view keeps `x-show`, so `@starting-style` gives the entry its start and the view's `x-transition`
+ * holds `display` through the exit, whose timing comes from the closed state's own rule (a
+ * transition takes the after-change style's). Not `allow-discrete` on `display`: Firefox does not
+ * transition `display`, and in the other engines it would hold a second time after Alpine's hold.
+ * Alpine holds for the first `transition-duration` listed, so each exit's longest transition is
+ * listed first. Reduced motion zeroes both duration tokens (tokens/motion.css).
  * Below `expanded` it slides, from whichever edge `data-md-side` names in the document's direction;
  * once `standard` makes it co-planar it only fades (an in-flow box does not need to travel). Every
  * state rule matches the sheet and scrim as the root's children, so a sheet nested in an open one
@@ -84,10 +87,9 @@
         color: var(--md-sys-color-on-surface);
         box-shadow: var(--md-sys-elevation-1);
         translate: var(--sheet-offset) 0;
-        transition-property: translate, display;
+        transition-property: translate;
         transition-duration: var(--md-sys-motion-effects-default-duration);
         transition-timing-function: var(--md-sys-motion-easing-emphasized-accelerate);
-        transition-behavior: allow-discrete;
     }
 
     [data-md-drawer-sheet][data-md-side='end'] {
@@ -167,7 +169,7 @@
             background-color: var(--md-sys-color-surface);
             box-shadow: none;
             opacity: 0;
-            transition-property: opacity, display;
+            transition-property: opacity;
             transition-duration: var(--md-sys-motion-effects-default-duration);
             transition-timing-function: var(--md-sys-motion-easing-emphasized-accelerate);
         }