Add networking layer and wire up v9 login flow with unit tests.

Introduce APIClient/AuthAPI, complete login with multi-account selection, and polish the login card UI with shadow and keyboard dismiss.

Co-authored-by: Cursor <cursoragent@cursor.com>

suixinkanTests/LoginViewModelTests.swift

@@ -0,0 +1,202 @@
+//
+//  LoginViewModelTests.swift
+//  suixinkanTests
+//
+
+import XCTest
+@testable import suixinkan
+
+@MainActor
+/// 登录页 ViewModel 测试，覆盖手机号规范化、表单校验和登录流程。
+final class LoginViewModelTests: XCTestCase {
+    func testNormalizeUsernameCountryCodeRemovesChinaPrefix() {
+        let viewModel = LoginViewModel()
+        viewModel.updateAccount("+86 186 5185 7230")
+
+        viewModel.normalizeUsernameCountryCodeIfNeeded()
+
+        XCTAssertEqual(viewModel.normalizedUsername, "18651857230")
+        XCTAssertTrue(viewModel.isValidPhone)
+    }
+
+    func testIsLoginEnabledRequiresValidPhoneAndNonEmptyPassword() {
+        let viewModel = LoginViewModel()
+        viewModel.updateAccount("18651857230")
+        viewModel.updatePassword(" secret123 ")
+
+        XCTAssertTrue(viewModel.isLoginEnabled)
+        XCTAssertEqual(viewModel.trimmedPassword, "secret123")
+    }
+
+    func testValidateForLoginReturnsExpectedErrorsInOrder() {
+        let viewModel = LoginViewModel()
+        viewModel.updateAccount("12345")
+        viewModel.updatePassword("secret123")
+        viewModel.togglePrivacyChecked()
+        XCTAssertEqual(viewModel.validateForLogin(), .invalidPhone)
+
+        viewModel.updateAccount("18651857230")
+        viewModel.updatePassword("   ")
+        XCTAssertEqual(viewModel.validateForLogin(), .emptyPassword)
+
+        viewModel.updatePassword("secret123")
+        viewModel.togglePrivacyChecked()
+        XCTAssertEqual(viewModel.validateForLogin(), .privacyUnchecked)
+    }
+
+    func testLoginWithSingleAccountAutoCompletesSetUser() async throws {
+        let loginJSON = """
+        {
+          "code": 100000,
+          "msg": "success",
+          "data": {
+            "token": "temp-token",
+            "scenic_users": [
+              {
+                "account_type": "scenic_user",
+                "id": 101,
+                "user_id": 101,
+                "scenic_user_id": 101,
+                "ss_user_id": 101,
+                "username": "scenic_admin",
+                "real_name": "张三",
+                "nickname": "张三",
+                "phone": "13800138000",
+                "scenic_id": 10,
+                "scenic_name": "示例景区",
+                "is_current": false
+              }
+            ],
+            "store_users": []
+          }
+        }
+        """.data(using: .utf8)!
+
+        let setUserJSON = """
+        {
+          "code": 100000,
+          "msg": "success",
+          "data": {
+            "token": "business-token-scenic",
+            "scenic_users": [],
+            "store_users": []
+          }
+        }
+        """.data(using: .utf8)!
+
+        let session = MockURLSession(responses: [loginJSON, setUserJSON])
+        let api = AuthAPI(client: APIClient(environment: .testing, session: session))
+        let viewModel = LoginViewModel()
+        viewModel.updateAccount("18651857230")
+        viewModel.updatePassword("secret123")
+        viewModel.togglePrivacyChecked()
+
+        let resolution = try await viewModel.login(authAPI: api)
+
+        guard case .completed(let response) = resolution else {
+            return XCTFail("单账号登录应直接完成")
+        }
+        XCTAssertEqual(response.token, "business-token-scenic")
+        XCTAssertFalse(viewModel.isLoading)
+        XCTAssertNil(viewModel.pendingAccountSelection)
+        XCTAssertEqual(session.requests.map { $0.url?.path }, [
+            "/api/app/v9/login",
+            "/api/app/v9/set-user",
+        ])
+    }
+
+    func testLoginWithMultipleAccountsNeedsSelection() async throws {
+        let loginJSON = """
+        {
+          "code": 100000,
+          "msg": "success",
+          "data": {
+            "token": "person-temp-token",
+            "scenic_users": [
+              {
+                "account_type": "scenic_user",
+                "id": 101,
+                "user_id": 101,
+                "scenic_user_id": 101,
+                "ss_user_id": 101,
+                "username": "scenic_admin",
+                "real_name": "张三",
+                "nickname": "张三",
+                "phone": "13800138000",
+                "scenic_id": 10,
+                "scenic_name": "示例景区",
+                "is_current": false
+              }
+            ],
+            "store_users": [
+              {
+                "account_type": "store_user",
+                "id": 201,
+                "user_id": 201,
+                "store_user_id": 201,
+                "username": "store_admin",
+                "user_name": "store_admin",
+                "real_name": "李四",
+                "phone": "13900139000",
+                "avatar": "",
+                "scenic_id": 10,
+                "scenic_name": "示例景区",
+                "store_id": 20,
+                "store_name": "示例门店",
+                "is_current": false
+              }
+            ]
+          }
+        }
+        """.data(using: .utf8)!
+
+        let session = MockURLSession(responses: [loginJSON])
+        let api = AuthAPI(client: APIClient(environment: .testing, session: session))
+        let viewModel = LoginViewModel()
+        viewModel.updateAccount("18651857230")
+        viewModel.updatePassword("secret123")
+        viewModel.togglePrivacyChecked()
+
+        let resolution = try await viewModel.login(authAPI: api)
+
+        guard case .needsAccountSelection(let payload) = resolution else {
+            return XCTFail("多账号登录应进入账号选择")
+        }
+        XCTAssertEqual(payload.tempToken, "person-temp-token")
+        XCTAssertEqual(payload.accounts.map(\.businessUserId), [101, 201])
+        XCTAssertNotNil(viewModel.pendingAccountSelection)
+        XCTAssertEqual(session.requests.count, 1)
+    }
+
+    func testLoginThrowsWhenNoAvailableAccounts() async {
+        let loginJSON = """
+        {
+          "code": 100000,
+          "msg": "success",
+          "data": {
+            "token": "person-temp-token",
+            "scenic_users": [],
+            "store_users": []
+          }
+        }
+        """.data(using: .utf8)!
+
+        let session = MockURLSession(responses: [loginJSON])
+        let api = AuthAPI(client: APIClient(environment: .testing, session: session))
+        let viewModel = LoginViewModel()
+        viewModel.updateAccount("18651857230")
+        viewModel.updatePassword("secret123")
+        viewModel.togglePrivacyChecked()
+
+        do {
+            _ = try await viewModel.login(authAPI: api)
+            XCTFail("没有可用账号时应抛出错误")
+        } catch let error as LoginFlowError {
+            guard case .noAvailableAccount = error else {
+                return XCTFail("期望 noAvailableAccount，实际为 \(error)")
+            }
+        } catch {
+            XCTFail("意外错误: \(error)")
+        }
+    }
+}