chore: core 多模块骨架

IosClientKit/Sources/CoreUI/ErrorView.swift

@@ -0,0 +1,22 @@
+import SwiftUI
+
+/// 错误占位视图（带重试）。
+public struct ErrorView: View {
+    private let message: String
+    private let retry: () -> Void
+
+    public init(message: String, retry: @escaping () -> Void) {
+        self.message = message
+        self.retry = retry
+    }
+
+    public var body: some View {
+        ContentUnavailableView {
+            Label("出错了", systemImage: "exclamationmark.triangle")
+        } description: {
+            Text(message)
+        } actions: {
+            Button("重试", action: retry)
+        }
+    }
+}