feat(chat-room-bg): 배경 이미지 변경 기능 추가

SodaLive/Sources/Chat/Character/Detail/Gallery/CharacterDetailGalleryView.swift

@@ -10,7 +10,7 @@ import SwiftUI
 struct CharacterDetailGalleryView: View {
     @StateObject var viewModel = CharacterDetailGalleryViewModel()
     
-    private let columns = Array(repeating: GridItem(.flexible()), count: 3)
+    private let columns = Array(repeating: GridItem(.flexible(), spacing: 0), count: 3)
     let characterId: Int
     
     // 계산된 속성들
@@ -30,7 +30,7 @@ struct CharacterDetailGalleryView: View {
                 
                 // 갤러리 그리드
                 ScrollView {
-                    LazyVGrid(columns: columns, spacing: 2) {
+                    LazyVGrid(columns: columns, spacing: 0) {
                         ForEach(Array(viewModel.galleryItems.enumerated()), id: \.element.id) { index, item in
                             galleryImageView(item: item, index: index)
                                 .onAppear {
@@ -38,7 +38,7 @@ struct CharacterDetailGalleryView: View {
                                 }
                         }
                     }
-                    .padding(.horizontal, 0)
+                    .frame(width: screenSize().width)
                 }
                 
                 Spacer()