Ask breakpoints.js, not Tailwind's screens, for a window class

Plan step 16. `navigation.js` takes its standard-rail threshold from
`from('expanded')` (840px) instead of the 64rem it had, and `navigation.css`'s
three 64rem queries follow, so the whole expanded class gets the in-layout
collapsible rail M3 asks for rather than one that opens over a scrim (N-06);
its two 40rem queries become 37.5rem, the compact/medium boundary the bar's own
container query already used (N-07). `search.js` and `datepicker.js` swap their
39.99rem media strings for `upTo('medium')`, so the full-screen search view and
the modal date picker end at 600px, not 640px.

The time picker's landscape layout stops keying on width at all: M3 swaps it on
orientation and viewport height, so it is now landscape plus a window too short
for the upright dial (35rem, the dialog's own height), and the two dial-shrink
rules key on height alone.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Qwx5USif3wFFmxtHg5U1g9

resources/js/search.js

@@ -4,11 +4,11 @@
  * Focus or a press on the bar opens the view; Escape, the back arrow, a press outside, focus
  * leaving the search, or choosing a result closes it. ArrowDown from the input moves into the
  * results and the arrow keys walk them; ArrowUp past the first result returns to the input. On a
- * compact window (below `sm`) the view is full screen and modal: focus stays in it and the page
- * behind does not scroll. The results themselves are the caller's, rendered by Livewire into the
- * view as the query changes.
+ * compact window (below `medium`, 600px) the view is full screen and modal: focus stays in it and
+ * the page behind does not scroll — M3 docks the view from medium upwards. The results themselves
+ * are the caller's, rendered by Livewire into the view as the query changes.
  */
-const COMPACT = '(max-width: 39.99rem)'
+import { upTo } from './breakpoints.js'
 
 const FOCUSABLE = 'a[href], button:not([disabled]), input:not([disabled]), select:not([disabled]), textarea:not([disabled]), [tabindex]:not([tabindex="-1"])'
 
@@ -26,7 +26,7 @@ document.addEventListener('alpine:init', () => {
         closedAt: -Infinity,
 
         init() {
-            const query = window.matchMedia(COMPACT)
+            const query = upTo('medium')
 
             this.compact = query.matches
             query.addEventListener('change', (event) => (this.compact = event.matches))