fix: Always update local URL first, then RSC

This is because relying only on the Next.js router for
URL updates makes it dependent on the RSC payload
to resolve, which is not the case in some situations:
- Offline or poor network connection
- Requests waterfalling when updating too quickly

Instead, the browser's history API is used for state management,
and optionally on non-shallow updates we can tell the server
about the updated URL to re-render and stream in RSC payloads.

packages/next-usequerystate/src/update-queue.ts

@@ -140,29 +140,27 @@ function flushUpdateQueue(router: Router) {
   const url = query ? `?${query}${hash}` : `${path}${hash}`
   debug('[nuqs queue] Updating url: %s', url)
   try {
-    if (options.shallow) {
-      const updateUrl =
-        options.history === 'push'
-          ? window.history.pushState
-          : window.history.replaceState
-      updateUrl.call(
-        window.history,
-        window.history.state,
-        // Our own updates have a marker to prevent syncing
-        // when the URL changes (we've already sync'd them up
-        // via `emitter.emit(key, newValue)` above, without
-        // going through the parsers).
-        NOSYNC_MARKER,
-        url
-      )
-      if (options.scroll) {
-        window.scrollTo(0, 0)
-      }
-    } else {
+    // First, update the URL locally without triggering a network request,
+    // this allows keeping a reactive URL if the network is slow.
+    const updateMethod =
+      options.history === 'push' ? history.pushState : history.replaceState
+    updateMethod.call(
+      history,
+      history.state,
+      // Our own updates have a marker to prevent syncing
+      // when the URL changes (we've already sync'd them up
+      // via `emitter.emit(key, newValue)` above, without
+      // going through the parsers).
+      NOSYNC_MARKER,
+      url
+    )
+    if (options.scroll) {
+      window.scrollTo(0, 0)
+    }
+    if (!options.shallow) {
       // Call the Next.js router to perform a network request
-      const updateUrl =
-        options.history === 'push' ? router.push : router.replace
-      updateUrl.call(router, url, { scroll: options.scroll })
+      // and re-render server components.
+      router.replace(url, { scroll: false })
     }
     return search
   } catch (error) {