feat(chat-room-bg): 배경 이미지 변경 기능 추가

SodaLive/Sources/Chat/Talk/Room/ChatRoomView.swift

@@ -249,7 +249,14 @@ struct ChatRoomView: View {
             }
             
             if viewModel.isShowingChangeBgView {
-                ChatBgSelectionView()
+                ChatBgSelectionView(
+                    characterId: viewModel.characterId,
+                    selectedBgImageId: viewModel.chatRoomBgImageId,
+                    onTapBgImage: {
+                        viewModel.setBackgroundImage(imageItem: $0)
+                    },
+                    isShowing: $viewModel.isShowingChangeBgView
+                )
             }
             
             if viewModel.isShowingChatResetConfirmDialog {
@@ -325,19 +332,28 @@ struct ChatRoomBgView: View {
     let url: String?
     
     var body: some View {
-        ZStack {
-            if let url = url {
-                KFImage(URL(string: url))
-                    .resizable()
-                    .aspectRatio(4/5, contentMode: .fill)
-                    .frame(maxWidth: screenSize().width)
+        GeometryReader { geo in
+            let width = geo.size.width
+            let height = width * 5 / 4
+            
+            ZStack {
+                if let url = url {
+                    KFImage(URL(string: url))
+                        .resizable()
+                        .scaledToFill()
+                        .frame(width: width, height: height)
+                        .clipped()
+                        .ignoresSafeArea()
+                }
+                
+                Color.black
+                    .opacity(0.6)
                     .ignoresSafeArea()
             }
-            
-            Color.black
-                .opacity(0.6)
-                .ignoresSafeArea()
+            .frame(width: width, height: height)
+            .clipped()
         }
+        .aspectRatio(4/5, contentMode: .fit)
     }
 }