fix(updates): keep the update modal's footer buttons on one line

The footer wrapped every label mid-word ("Check / now", "Copy / command")
because nothing stopped the text breaking and the modal was too narrow to
hold four buttons.

Three changes, smallest first:

  - `whitespace-nowrap` on the footer container. `white-space` inherits, so
    one class keeps every label on its own line without touching each button.
  - `flex-wrap` alongside it, so a translation that still outgrows the modal
    breaks the ROW rather than the words.
  - `max-w-lg` -> `max-w-2xl` on the dialog.

Those alone were not enough in Vietnamese: the button's restarting label is
a full sentence ("Đã build xong — đang khởi động lại bảng điều khiển...",
52 chars), which put the row over the width on its own. That sentence is
already shown in the status banner directly above the footer, so the button
now uses a new short `restartingShort` key and the banner keeps the full
one unchanged.

client/src/components/UpdateNotifier.tsx

@@ -306,7 +306,9 @@ export function UpdateNotifier() {
         if (e.target === e.currentTarget) dismiss();
       }}
     >
-      <div className="w-full max-w-lg card shadow-2xl animate-slide-up overflow-hidden">
+      {/* max-w-2xl, not lg: the footer carries up to four buttons and the
+          longest label is a whole sentence ("restarting the dashboard…"). */}
+      <div className="w-full max-w-2xl card shadow-2xl animate-slide-up overflow-hidden">
         {/* Header */}
         <div className="flex items-start justify-between gap-3 px-5 py-4 border-b border-border">
           <div className="flex items-center gap-3 min-w-0">
@@ -432,7 +434,10 @@ export function UpdateNotifier() {
         </div>
 
         {/* Footer */}
-        <div className="flex items-center justify-end gap-2 px-5 py-3 border-t border-border bg-surface-2/40">
+        {/* `whitespace-nowrap` inherits, so one class keeps every label on its
+            own single line; `flex-wrap` then breaks the ROW instead of the
+            words if a translation still outgrows the modal. */}
+        <div className="flex flex-wrap items-center justify-end gap-2 whitespace-nowrap px-5 py-3 border-t border-border bg-surface-2/40">
           <button
             type="button"
             onClick={checkNow}
@@ -473,7 +478,10 @@ export function UpdateNotifier() {
               ) : (
                 <Zap className="w-4 h-4" aria-hidden />
               )}
-              {applying ? t("updating") : restarting ? t("restarting") : t("updateNow")}
+              {/* `restartingShort`, not `restarting`: the full sentence is
+                  already in the banner above, and a whole sentence on a button
+                  is what forced this footer onto two lines. */}
+              {applying ? t("updating") : restarting ? t("restartingShort") : t("updateNow")}
             </button>
           ) : null}
         </div>