fix: 修复 Tailwind CSS border 类名冲突（border-border-default 改为直接颜色值）

frontend/src/components/ui/DataTable.tsx

@@ -48,10 +48,10 @@ export function DataTable<T>({
     align === 'right' ? 'text-right' : align === 'center' ? 'text-center' : 'text-left'
 
   return (
-    <div className={clsx('overflow-x-auto border border-border-default rounded-card bg-surface-card', className)}>
+    <div className={clsx('overflow-x-auto border border-[#DDE1DD] rounded-card bg-surface-card', className)}>
       <table className="w-full text-sm">
         <thead>
-          <tr className="border-b border-border-default bg-surface-muted">
+          <tr className="border-b border-[#DDE1DD] bg-surface-muted">
             {columns.map((col) => (
               <th
                 key={col.key}
@@ -99,7 +99,7 @@ export function DataTable<T>({
                 key={rowKey(row)}
                 onClick={onRowClick ? () => onRowClick(row) : undefined}
                 className={clsx(
-                  'border-b border-border-subtle transition-colors',
+                  'border-b border-[#ECEEEC] transition-colors',
                   onRowClick && 'cursor-pointer hover:bg-surface-muted',
                 )}
               >

frontend/src/components/ui/FilterBar.tsx

@@ -40,7 +40,7 @@ export function FilterBar({
               value={searchValue || ''}
               onChange={(e) => onSearchChange(e.target.value)}
               placeholder={searchPlaceholder}
-              className="w-full pl-8 pr-3 py-1.5 rounded-md border border-border-default bg-surface-card text-sm text-ink-900 focus:outline-none focus:ring-2 focus:ring-brand-600/30 focus:border-brand-600 transition-colors"
+              className="w-full pl-8 pr-3 py-1.5 rounded-md border border-[#DDE1DD] bg-surface-card text-sm text-ink-900 focus:outline-none focus:ring-2 focus:ring-brand-600/30 focus:border-brand-600 transition-colors"
             />
           </div>
         )}