feat: 添加Swift Package管理和API功能模块

新增Package.swift和Package.resolved文件以支持Swift Package管理，创建API相关文件（API.swift、APICaller.swift、APIConstants.swift、APIEndpoints.swift、APIService.swift、APILogger.swift、APIModels.swift、Integration-Guide.md）以实现API请求管理和网络交互功能，增强项目的功能性和可扩展性。同时更新.gitignore以排除构建文件和临时文件。

yana/Features/LoginFeature.swift

@@ -0,0 +1,83 @@
+import Foundation
+import ComposableArchitecture
+
+struct LoginResponse: Codable, Equatable {
+    let status: String
+    let message: String?
+    let token: String?
+}
+
+@Reducer
+struct LoginFeature {
+    @ObservableState
+    struct State: Equatable {
+        var account: String = ""
+        var password: String = ""
+        var isLoading = false
+        var error: String?
+        
+        #if DEBUG
+        init() {
+            self.account = "3184"
+            self.password = "a0d5da073d14731cc7a01ecaa17b9174"
+        }
+        #endif
+    }
+    
+    enum Action: Equatable {
+        case updateAccount(String)
+        case updatePassword(String)
+        case login
+        case loginResponse(TaskResult<LoginResponse>)
+    }
+    
+    var body: some ReducerOf<Self> {
+        Reduce { state, action in
+            switch action {
+            case let .updateAccount(account):
+                state.account = account
+                return .none
+                
+            case let .updatePassword(password):
+                state.password = password
+                return .none
+                
+            case .login:
+                state.isLoading = true
+                state.error = nil
+                
+                let loginBody = [
+                    "account": state.account,
+                    "password": state.password
+                ]
+                
+                return .run { send in
+                    do {
+                        let response: LoginResponse = try await APIClientManager.shared.post(
+                            path: APIConstants.Endpoints.login,
+                            body: loginBody,
+                            headers: APIConstants.defaultHeaders
+                        )
+                        await send(.loginResponse(.success(response)))
+                    } catch {
+                        await send(.loginResponse(.failure(error)))
+                    }
+                }
+                
+            case let .loginResponse(.success(response)):
+                state.isLoading = false
+                if response.status == "success" {
+                    // TODO: 处理登录成功，保存 token 等
+                } else {
+                    state.error = response.message ?? "登录失败"
+                }
+                return .none
+                
+            case let .loginResponse(.failure(error)):
+                state.isLoading = false
+                state.error = error.localizedDescription
+                return .none
+            }
+        }
+    }
+}