feat(character): 캐릭터 메인 화면 구현 및 Combine 기반 리팩터링

- 배너/최근/신규/큐레이션 섹션 UI 구성 및 데이터 바인딩
- 네트워크 이미지 로더를 Kingfisher(KFImage)로 교체하여 캐싱/재시도 지원
- CharacterApi에 토큰 헤더 포함, GET /api/chat/character/main 연동

SodaLive/Sources/Chat/Character/CharacterSectionView.swift

@@ -0,0 +1,49 @@
+//
+//  CharacterSectionView.swift
+//  SodaLive
+//
+//  Created by klaus on 8/29/25.
+//
+
+import SwiftUI
+
+struct CharacterSectionView: View {
+    let title: String
+    let items: [Character]
+    var onTap: (Character) -> Void = { _ in }
+    
+    var body: some View {
+        VStack(alignment: .leading, spacing: 12) {
+            Text(title)
+                .font(.custom(Font.preBold.rawValue, size: 20))
+                .foregroundColor(.white)
+                .padding(.horizontal, 24)
+            
+            ScrollView(.horizontal, showsIndicators: false) {
+                HStack(spacing: 16) {
+                    ForEach(items.indices, id: \.self) { idx in
+                        let item = items[idx]
+                        CharacterItemView(
+                            character: item,
+                            size: screenSize().width * 0.42
+                        )
+                        .onTapGesture { onTap(item) }
+                    }
+                }
+                .padding(.horizontal, 24)
+            }
+        }
+    }
+}
+
+#Preview {
+    CharacterSectionView(
+        title: "신규 캐릭터",
+        items: [
+            Character(characterId: 1, name: "찰리", description: "새로운 친구", imageUrl: "https://picsum.photos/300"),
+            Character(characterId: 2, name: "데이지", description: "", imageUrl: "https://picsum.photos/300")
+        ]
+    )
+    .padding()
+    .background(Color.black)
+}