feat(admin): design system audit fixes

- Add CSS design tokens for consistency (--admin-danger-hover, --admin-accent-dot, shadow-md warm tone)
- Replace unicode icons with inline SVG (⋮, ✕, ▼, ▶)
- Consolidate duplicate PageHeader/AdminPageHeader components
- Standardize border-radius (rounded-xl → rounded-lg for ViewModeTabs)
- Remove hardcoded brand UUID in products page
- Replace hardcoded bg-red-600 with CSS variables in delete buttons
- Add AdminButton, AdminFilterTabs, AdminSearchInput, PageHeader design system components
- Fix GlassModal and AdminModal close button styling
- Remove duplicate 'New Lot' button on Route Trace dashboard

src/components/admin/StopsHeaderActions.tsx

@@ -4,6 +4,7 @@ import { useState } from "react";
 import ScheduleImportModal from "@/components/admin/ScheduleImportModal";
 import AddStopModal from "@/components/admin/AddStopModal";
 import { useRouter } from "next/navigation";
+import { AdminButton } from "@/components/admin/design-system";
 
 type Props = {
   brandId: string;
@@ -25,24 +26,28 @@ export default function StopsHeaderActions({ brandId }: Props) {
   return (
     <>
       <div className="flex gap-3">
-        <button
+        <AdminButton
+          variant="secondary"
           onClick={() => setShowImport(true)}
-          className="flex items-center gap-2 rounded-xl border border-stone-300 bg-white px-4 py-2.5 text-sm font-medium text-stone-700 hover:bg-stone-50 hover:border-stone-400 transition-colors"
+          icon={
+            <svg className="h-4 w-4" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2}>
+              <path strokeLinecap="round" strokeLinejoin="round" d="M4 16v1a3 3 0 003 3h10a3 3 0 003-3v-1m-4-8l-4-4m0 0L8 8m4-4v12" />
+            </svg>
+          }
         >
-          <svg className="h-4 w-4" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2}>
-            <path strokeLinecap="round" strokeLinejoin="round" d="M4 16v1a3 3 0 003 3h10a3 3 0 003-3v-1m-4-8l-4-4m0 0L8 8m4-4v12" />
-          </svg>
           Upload Schedule
-        </button>
-        <button
+        </AdminButton>
+        <AdminButton
+          variant="primary"
           onClick={() => setShowAdd(true)}
-          className="flex items-center gap-2 rounded-xl bg-emerald-600 hover:bg-emerald-500 active:bg-emerald-700 px-5 py-2.5 text-sm font-semibold text-white transition-colors shadow-sm shadow-emerald-200"
+          icon={
+            <svg className="h-4 w-4" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2.5}>
+              <path strokeLinecap="round" strokeLinejoin="round" d="M12 4v16m8-8H4" />
+            </svg>
+          }
         >
-          <svg className="h-4 w-4" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2.5}>
-            <path strokeLinecap="round" strokeLinejoin="round" d="M12 4v16m8-8H4" />
-          </svg>
           Add Stop
-        </button>
+        </AdminButton>
       </div>
 
       {showImport && (