feat: feature 多模块骨架

IosClientKit/Sources/FeatureHome/HomeViewModel.swift

@@ -0,0 +1,34 @@
+import CoreDomain
+import CoreModel
+import Observation
+
+@MainActor
+@Observable
+public final class HomeViewModel {
+    public private(set) var uiState: HomeUiState = .loading
+
+    private let homeUseCase: HomeUseCase
+    private var loadTask: Task<Void, Never>?
+
+    public init(homeUseCase: HomeUseCase) {
+        self.homeUseCase = homeUseCase
+    }
+
+    public func load() {
+        // flatMapLatest 的等价：新 load 前先取消旧的观察。
+        loadTask?.cancel()
+        loadTask = Task { [weak self] in
+            guard let self else { return }
+            self.uiState = .loading
+            do {
+                for try await data in self.homeUseCase.observeHome() {
+                    self.uiState = data.habits.isEmpty ? .empty : .success(data)
+                }
+            } catch is CancellationError {
+                // 被更新的 load() 取代，保持当前状态即可。
+            } catch {
+                self.uiState = .error(error.localizedDescription)
+            }
+        }
+    }
+}