refactor: 전체 프론트엔드 하드코딩 색상 → CSS 변수 일괄 치환

447+ 파일, 4500+ 줄 변경:
- gray-* → border/bg-muted/text-foreground/text-muted-foreground
- blue-* → primary/ring
- red-* → destructive
- green-* → emerald (일관성)
- indigo-* → primary
- yellow/orange → amber (통일)
- dark mode 변형도 시맨틱 토큰으로 변환

Made-with: Cursor

frontend/components/dataflow/node-editor/nodes/AggregateNode.tsx

@@ -28,7 +28,7 @@ export const AggregateNode = memo(({ data, selected }: NodeProps<AggregateNodeDa
   return (
     <div
       className={`min-w-[280px] rounded-lg border-2 bg-white shadow-md transition-all ${
-        selected ? "border-purple-500 shadow-lg" : "border-gray-200"
+        selected ? "border-purple-500 shadow-lg" : "border-border"
       }`}
     >
       {/* 헤더 */}
@@ -71,28 +71,28 @@ export const AggregateNode = memo(({ data, selected }: NodeProps<AggregateNodeDa
         {aggregationCount > 0 ? (
           <div className="space-y-2">
             {data.aggregations.slice(0, 4).map((agg, idx) => (
-              <div key={agg.id || idx} className="rounded bg-gray-50 p-2">
+              <div key={agg.id || idx} className="rounded bg-muted p-2">
                 <div className="flex items-center justify-between">
                   <span className="rounded bg-purple-600 px-1.5 py-0.5 text-xs font-medium text-white">
                     {AGGREGATE_FUNCTION_LABELS[agg.function] || agg.function}
                   </span>
-                  <span className="text-xs text-gray-500">
+                  <span className="text-xs text-muted-foreground">
                     {agg.outputFieldLabel || agg.outputField}
                   </span>
                 </div>
-                <div className="mt-1 text-xs text-gray-600">
+                <div className="mt-1 text-xs text-muted-foreground">
                   {agg.sourceFieldLabel || agg.sourceField}
                 </div>
               </div>
             ))}
             {data.aggregations.length > 4 && (
-              <div className="text-xs text-gray-400 text-center">
+              <div className="text-xs text-muted-foreground/70 text-center">
                 ... 외 {data.aggregations.length - 4}개
               </div>
             )}
           </div>
         ) : (
-          <div className="py-4 text-center text-xs text-gray-400">집계 연산 없음</div>
+          <div className="py-4 text-center text-xs text-muted-foreground/70">집계 연산 없음</div>
         )}
       </div>