feat: #22 知识库分类管理页面

- KnowledgeFolder 模型 + CreateFolderRequest
- KnowledgeFolderService (list/create/update/delete)
- FolderManageView: 列表 + 新建/重命名/删除
- LibraryDetailPage 菜单「分类管理」入口

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

AIStudyApp/AIStudyApp/Core/Models/APIModels.swift

@@ -600,6 +600,23 @@ struct BatchAcceptRequest: Codable {
     let sourceId: String
 }
 
+// MARK: - Knowledge Folder
+
+struct KnowledgeFolder: Codable, Identifiable {
+    let id: String
+    let knowledgeBaseId: String?
+    let parentId: String?
+    let name: String
+    let sortOrder: Int?
+    let createdAt: String?
+    let updatedAt: String?
+}
+
+struct CreateFolderRequest: Codable {
+    let name: String
+    let parentId: String?
+}
+
 // MARK: - Knowledge Source
 
 struct KnowledgeSource: Codable, Identifiable {

AIStudyApp/AIStudyApp/Core/Services/APIService.swift

@@ -142,6 +142,31 @@ class KnowledgeBaseService {
     }
 }
 
+// MARK: - Knowledge Folder
+
+@MainActor
+class KnowledgeFolderService {
+    static let shared = KnowledgeFolderService()
+    private let client = APIClient.shared
+
+    func list(kbId: String) async throws -> [KnowledgeFolder] {
+        return try await client.request("/knowledge-bases/\(kbId)/folders")
+    }
+
+    func create(kbId: String, name: String, parentId: String? = nil) async throws -> KnowledgeFolder {
+        let body = CreateFolderRequest(name: name, parentId: parentId)
+        return try await client.request("/knowledge-bases/\(kbId)/folders", method: "POST", body: body)
+    }
+
+    func update(kbId: String, folderId: String, name: String) async throws -> KnowledgeFolder {
+        return try await client.request("/knowledge-bases/\(kbId)/folders/\(folderId)", method: "PATCH", body: ["name": name])
+    }
+
+    func delete(kbId: String, folderId: String) async throws -> GenericSuccessResponse {
+        return try await client.request("/knowledge-bases/\(kbId)/folders/\(folderId)", method: "DELETE")
+    }
+}
+
 // MARK: - Knowledge Items
 
 @MainActor

AIStudyApp/AIStudyApp/Features/Library/FolderManageView.swift

@@ -0,0 +1,102 @@
+import SwiftUI
+
+struct FolderManageView: View {
+    let knowledgeBaseId: String
+    @Environment(\.dismiss) private var dismiss
+    @State private var folders: [KnowledgeFolder] = []
+    @State private var isLoading = false
+    @State private var showCreateAlert = false
+    @State private var showRenameAlert = false
+    @State private var newFolderName = ""
+    @State private var renameFolderId: String?
+    @State private var renameName = ""
+
+    var body: some View {
+        NavigationStack {
+            ZStack {
+                Color.zxBg0.ignoresSafeArea()
+                if isLoading && folders.isEmpty {
+                    ProgressView().tint(Color.zxPurple)
+                } else if folders.isEmpty {
+                    Text("暂无分类").font(.system(size: 14)).foregroundColor(Color.zxF04)
+                } else {
+                    List {
+                        ForEach(folders) { f in
+                            HStack {
+                                Image(systemName: "folder")
+                                    .foregroundColor(Color.zxF05)
+                                Text(f.name)
+                                    .font(.system(size: 14))
+                                    .foregroundColor(Color.zxF0)
+                                Spacer()
+                            }
+                            .padding(.vertical, 4)
+                            .swipeActions(edge: .trailing) {
+                                Button(role: .destructive) {
+                                    Task {
+                                        try? await KnowledgeFolderService.shared.delete(kbId: knowledgeBaseId, folderId: f.id)
+                                        folders.removeAll { $0.id == f.id }
+                                    }
+                                } label: { Label("删除", systemImage: "trash") }
+                                Button {
+                                    renameFolderId = f.id
+                                    renameName = f.name
+                                    showRenameAlert = true
+                                } label: { Label("重命名", systemImage: "pencil") }
+                                .tint(Color.zxPurple)
+                            }
+                        }
+                    }
+                    .listStyle(.plain)
+                    .scrollContentBackground(.hidden)
+                }
+            }
+            .navigationTitle("分类管理")
+            .navigationBarTitleDisplayMode(.inline)
+            .toolbar {
+                ToolbarItem(placement: .topBarTrailing) {
+                    Button {
+                        newFolderName = ""
+                        showCreateAlert = true
+                    } label: {
+                        Image(systemName: "plus").font(.system(size: 16)).foregroundColor(Color.zxF05)
+                    }
+                }
+                ToolbarItem(placement: .topBarLeading) {
+                    Button("完成") { dismiss() }
+                        .font(.system(size: 14)).foregroundColor(Color.zxF05)
+                }
+            }
+            .alert("新建分类", isPresented: $showCreateAlert) {
+                TextField("分类名称", text: $newFolderName)
+                Button("取消", role: .cancel) {}
+                Button("创建") {
+                    Task {
+                        if let f = try? await KnowledgeFolderService.shared.create(kbId: knowledgeBaseId, name: newFolderName) {
+                            folders.append(f)
+                        }
+                    }
+                }
+            }
+            .alert("重命名", isPresented: $showRenameAlert) {
+                TextField("新名称", text: $renameName)
+                Button("取消", role: .cancel) {}
+                Button("确定") {
+                    if let fid = renameFolderId {
+                        Task {
+                            try? await KnowledgeFolderService.shared.update(kbId: knowledgeBaseId, folderId: fid, name: renameName)
+                            await load()
+                        }
+                    }
+                }
+            }
+            .task { await load() }
+        }
+    }
+
+    private func load() async {
+        isLoading = true
+        folders = (try? await KnowledgeFolderService.shared.list(kbId: knowledgeBaseId)) ?? []
+        isLoading = false
+    }
+}

AIStudyApp/AIStudyApp/Features/Library/LibrarySubpages.swift

@@ -143,6 +143,7 @@ struct LibraryDetailPage: View {
     @State private var showBatchDeleteConfirm = false
     @State private var detailTab = 0
     @State private var sortOption = 0
+    @State private var showFolderManager = false
     @State private var sources: [KnowledgeSource] = []
     @State private var isLoadingSources = false
 
@@ -340,9 +341,9 @@ struct LibraryDetailPage: View {
                             Label("添加知识点", image: "icon-plus")
                         }
                         Button {
-                            // TODO: create folder
+                            showFolderManager = true
                         } label: {
-                            Label("创建文件夹", image: "icon-folder")
+                            Label("分类管理", image: "icon-folder")
                         }
                         NavigationLink(value: Route.quizList(knowledgeBaseId: knowledgeBaseId)) {
                             Label("答题测验", image: "icon-pencil")
@@ -392,6 +393,9 @@ struct LibraryDetailPage: View {
             Text("确定要删除选中的 \(selectedIds.count) 个知识点吗？此操作不可恢复。")
         }
         .task { await viewModel.loadItems(knowledgeBaseId: knowledgeBaseId) }
+        .sheet(isPresented: $showFolderManager) {
+            FolderManageView(knowledgeBaseId: knowledgeBaseId)
+        }
         .onChange(of: sortOption) { _ in
             let (sb, od) = sortParams(sortOption)
             Task { await viewModel.loadItems(knowledgeBaseId: knowledgeBaseId, sortBy: sb, order: od) }