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/lib/registry/components/text-input/TextInputConfigPanel.tsx

@@ -189,7 +189,7 @@ export const TextInputConfigPanel: React.FC<TextInputConfigPanelProps> = ({ conf
 
             {/* 선택된 타입 설명 */}
             {config.autoGeneration?.type && config.autoGeneration.type !== "none" && (
-              <div className="text-xs text-gray-500">
+              <div className="text-xs text-muted-foreground">
                 {AutoGenerationUtils.getTypeDescription(config.autoGeneration.type)}
               </div>
             )}
@@ -379,7 +379,7 @@ export const TextInputConfigPanel: React.FC<TextInputConfigPanelProps> = ({ conf
               {/* 미리보기 */}
               <div className="space-y-1">
                 <Label className="text-xs">미리보기</Label>
-                <div className="rounded border bg-gray-100 p-2 text-xs">
+                <div className="rounded border bg-muted p-2 text-xs">
                   {AutoGenerationUtils.generatePreviewValue(config.autoGeneration)}
                 </div>
               </div>