feat(ios): IOS-M0-08~14 P2 辅助功能服务层全部补齐

M0-08 账号注销/设备管理：
  - UserService: requestAccountDeletion/cancelDeletion/listDevices/removeDevice

M0-09 Push Token/通知偏好：
  - NotificationService: markAllRead/getPreferences/updatePreferences/registerPushToken/removePushToken

M0-12 Review 生成卡片：
  - ReviewService: generateCards()

M0-13 FocusItems 完整操作：
  - FocusItemService: update()/complete()

KnowledgeBase update 接口已存在，服务层已接入

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

AIStudyApp/AIStudyApp/Core/Services/APIService.swift

@@ -69,6 +69,29 @@ class UserService {
     func updateProfileDetail(_ dto: UpdateProfileDataRequest) async throws -> UserProfileData {
         return try await client.request("/users/me/profile", method: "PATCH", body: dto)
     }
+
+    func requestAccountDeletion() async throws -> GenericSuccessResponse {
+        return try await client.request("/users/me/deletion-request", method: "POST")
+    }
+
+    func cancelDeletion() async throws -> GenericSuccessResponse {
+        return try await client.request("/users/me/deletion-request", method: "DELETE")
+    }
+
+    func listDevices() async throws -> [UserDevice] {
+        return try await client.request("/users/me/devices")
+    }
+
+    func removeDevice(id: String) async throws -> GenericSuccessResponse {
+        return try await client.request("/users/me/devices/\(id)", method: "DELETE")
+    }
+}
+
+struct UserDevice: Codable, Identifiable {
+    let id: String
+    let deviceName: String?
+    let deviceType: String?
+    let lastSeenAt: String?
 }
 
 // MARK: - Knowledge Base
@@ -234,6 +257,10 @@ class ReviewService {
         let body = SubmitReviewRequest(rating: rating, responseText: responseText)
         return try await client.request("/reviews/\(id)/submit", method: "POST", body: body)
     }
+
+    func generateCards() async throws -> GenericSuccessResponse {
+        return try await client.request("/reviews/generate-cards", method: "POST")
+    }
 }
 
 // MARK: - Focus Items
@@ -249,6 +276,17 @@ class FocusItemService {
             URLQueryItem(name: "limit", value: String(limit)),
         ])
     }
+
+    func update(id: String, masteryScore: Int? = nil, title: String? = nil) async throws -> FocusItem {
+        var body: [String: Any] = [:]
+        if let s = masteryScore { body["masteryScore"] = s }
+        if let t = title { body["title"] = t }
+        return try await client.request("/focus-items/\(id)", method: "PATCH", body: body)
+    }
+
+    func complete(id: String) async throws -> GenericSuccessResponse {
+        return try await client.request("/focus-items/\(id)/complete", method: "POST")
+    }
 }
 
 // MARK: - Activity & Stats
@@ -417,4 +455,34 @@ class NotificationService {
     func markRead(id: String) async throws -> NotificationItem {
         return try await client.request("/notifications/\(id)/read", method: "PATCH")
     }
+
+    func markAllRead() async throws -> GenericSuccessResponse {
+        return try await client.request("/notifications/read-all", method: "POST")
+    }
+
+    func getPreferences() async throws -> NotificationPreferences {
+        return try await client.request("/notifications/preferences")
+    }
+
+    func updatePreferences(_ dto: NotificationPreferences) async throws -> NotificationPreferences {
+        return try await client.request("/notifications/preferences", method: "PATCH", body: dto)
+    }
+
+    func registerPushToken(_ token: String) async throws -> GenericSuccessResponse {
+        return try await client.request("/notifications/push-token", method: "POST", body: ["token": token])
+    }
+
+    func removePushToken(_ token: String) async throws -> GenericSuccessResponse {
+        return try await client.request("/notifications/push-tokens/\(token)", method: "DELETE")
+    }
+}
+
+struct NotificationPreferences: Codable {
+    var reviewReminder: Bool?
+    var newFeatures: Bool?
+    var systemNotice: Bool?
+}
+
+struct FocusItemCompleteRequest: Codable {
+    let id: String
 }