feat: 新增 Fake 仓库实现（含可提交的打卡/计划与会话）

IosClientKit/Sources/CoreRepository/FakeSessionRepository.swift

@@ -0,0 +1,39 @@
+import Combine
+import CoreDomain
+import Foundation
+
+/// Fake 会话仓库（登录态在进程内共享，默认未登录）。
+public final class FakeSessionRepository: SessionRepository, @unchecked Sendable {
+    private let isLoggedIn = CurrentValueSubject<Bool, Never>(false)
+
+    public init() {}
+
+    public func observeIsLoggedIn() -> AsyncThrowingStream<Bool, Error> {
+        AsyncThrowingStream { continuation in
+            let cancellable = self.isLoggedIn.sink { continuation.yield($0) }
+            continuation.onTermination = { _ in cancellable.cancel() }
+        }
+    }
+
+    public func requestSmsCode(phone: String) async throws {
+        try await Task.sleep(for: .milliseconds(500))
+        guard phone.range(of: #"^1\d{10}$"#, options: .regularExpression) != nil else {
+            throw SessionError.invalidPhone
+        }
+    }
+
+    public func login(phone: String, code: String) async throws {
+        try await Task.sleep(for: .milliseconds(500))
+        guard code == "123456" else {
+            throw SessionError.wrongCode
+        }
+        guard phone == "13812341234" else {
+            throw SessionError.phoneNotMatched
+        }
+        isLoggedIn.value = true
+    }
+
+    public func logout() async throws {
+        isLoggedIn.value = false
+    }
+}