feat(image): 메인 홈, 채팅 - 톡 페이지에 DownsampledKFImage 적용

- 수평 리스트 HStack → LazyHStack으로 교체해 프리로딩/메모리 개선

SodaLive/Sources/Content/Main/V2/ContentMainBannerViewV2.swift

@@ -112,13 +112,11 @@ struct ContentMainBannerImageView: View {
     var body: some View {
         Group {
             if let boundURL {
-                KFImage(boundURL)
-                    .cancelOnDisappear(true)
-                    .downsampling(size: CGSize(width: width, height: height))
-                    .resizable()
-                    .scaledToFill()
-                    .frame(width: width, height: height)
-                    .cornerRadius(4.7)
+                DownsampledKFImage(
+                    url: boundURL,
+                    size: CGSize(width: width, height: height)
+                )
+                .cornerRadius(4.7)
             } else {
                 Color.clear
                     .frame(width: width, height: height)