feat(ios): 添加知识点 - 多选文件 + 标题可选 + 每个文件独立知识点

- 文件选择器改为多选（allowsMultipleSelection: true）
- 图片选择器支持多选（maxSelectionCount: 10）
- 标题改为可选，留空自动用文件名
- 每个文件独立上传 → 独立知识点
- 多文件时按钮显示"批量添加 (N个)"
- 已选文件可逐个删除
- 部分失败时显示 X/N 成功计数

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

AIStudyApp/AIStudyApp/Features/Library/LibrarySubpages.swift

@@ -113,15 +113,15 @@ struct AddKnowledgePage: View {
     @Environment(\.dismiss) private var dismiss
     @State private var title = ""
     @State private var content = ""
-    @State private var sourceType: SourceType = .manual
+    @State private var sourceType: SourceType = .file
-    @State private var selectedFileURL: URL?
+    @State private var selectedFiles: [SelectedFile] = []
-    @State private var selectedFileName = ""
-    @State private var selectedFileData: Data?
     @State private var isUploading = false
     @State private var isSaving = false
     @State private var showFilePicker = false
     @State private var showPhotoPicker = false
-    @State private var selectedPhotoItem: PhotosPickerItem?
+    @State private var selectedPhotoItems: [PhotosPickerItem] = []
+
+    struct SelectedFile: Identifiable { let id = UUID(); let name: String; let data: Data; let icon: String; let size: String }
 
     enum SourceType: String, CaseIterable { case manual = "手写", file = "文件" }
 
@@ -130,8 +130,8 @@ struct AddKnowledgePage: View {
             ScrollView { VStack(spacing: 16) {
                 // 标题
                 VStack(alignment: .leading, spacing: 8) {
-                    Text("标题").font(.system(size: 12, weight: .semibold)).foregroundColor(Color.zxF035)
+                    Text("标题（可选，留空使用文件名）").font(.system(size: 12, weight: .semibold)).foregroundColor(Color.zxF035)
-                    TextField("输入知识点标题", text: $title).font(.system(size: 15)).tint(Color.zxPurple)
+                    TextField("输入知识点标题，留空则用文件名", text: $title).font(.system(size: 15)).tint(Color.zxPurple)
                         .padding(.horizontal, 16).frame(height: 52)
                         .background(Color.zxFill004).clipShape(RoundedRectangle(cornerRadius: 14))
                         .overlay(RoundedRectangle(cornerRadius: 14).stroke(Color.zxBorder008, lineWidth: 1))
@@ -159,7 +159,6 @@ struct AddKnowledgePage: View {
 
                 case .file:
                     VStack(spacing: 10) {
-                        // 文件选择按钮
                         HStack(spacing: 8) {
                             Button { showFilePicker = true } label: {
                                 HStack {
@@ -185,28 +184,39 @@ struct AddKnowledgePage: View {
                             }
                         }
 
-                        // 已选文件
+                        // 已选文件列表
-                        if !selectedFileName.isEmpty {
+                        if !selectedFiles.isEmpty {
-                            HStack(spacing: 8) {
+                            VStack(spacing: 6) {
-                                Image(systemName: fileIcon).foregroundColor(Color.zxGreen)
+                                ForEach(selectedFiles) { f in
-                                Text(selectedFileName).font(.system(size: 13)).foregroundColor(Color.zxF0).lineLimit(1)
+                                    HStack(spacing: 8) {
-                                Spacer()
+                                        Image(systemName: f.icon).foregroundColor(Color.zxGreen)
-                                Text(formatFileSize).font(.system(size: 11)).foregroundColor(Color.zxF04)
+                                        Text(f.name).font(.system(size: 13)).foregroundColor(Color.zxF0).lineLimit(1)
+                                        Spacer()
+                                        Text(f.size).font(.system(size: 11)).foregroundColor(Color.zxF04)
+                                        Button {
+                                            selectedFiles.removeAll { $0.id == f.id }
+                                        } label: {
+                                            Image(systemName: "xmark.circle.fill").font(.system(size: 16)).foregroundColor(Color.zxF04)
+                                        }
+                                    }
+                                    .padding(.horizontal, 12).padding(.vertical, 8)
+                                    .background(Color.zxFill004)
+                                    .clipShape(RoundedRectangle(cornerRadius: 12))
+                                }
                             }
-                            .padding(12).background(Color.zxFill004)
-                            .clipShape(RoundedRectangle(cornerRadius: 12))
-                            .overlay(RoundedRectangle(cornerRadius: 12).stroke(Color.zxBorder008, lineWidth: 1))
                         }
 
-                        // 支持格式
+                        HStack {
-                        Text("支持 Markdown、TXT、PDF、图片（JPEG/PNG）")
+                            Image(systemName: "info.circle").font(.system(size: 11))
-                            .font(.system(size: 11)).foregroundColor(Color.zxF04)
+                            Text("支持多选，每个文件生成一个知识点")
+                        }
+                        .font(.system(size: 11)).foregroundColor(Color.zxF04)
                     }
 
                     if isUploading {
                         HStack(spacing: 8) {
                             ProgressView()
-                            Text("上传中...").font(.system(size: 13)).foregroundColor(Color.zxF04)
+                            Text("上传中 \(currentUploadIndex)/\(selectedFiles.count)...").font(.system(size: 13)).foregroundColor(Color.zxF04)
                         }
                     }
                 }
@@ -217,7 +227,7 @@ struct AddKnowledgePage: View {
                 } label: {
                     HStack(spacing: 8) {
                         if isSaving { ProgressView().tint(.white) }
-                        Text("保存").font(.system(size: 14, weight: .bold))
+                        Text(sourceType == .file && selectedFiles.count > 1 ? "批量添加 (\(selectedFiles.count) 个)" : "保存").font(.system(size: 14, weight: .bold))
                     }
                     .foregroundColor(.white).frame(maxWidth: .infinity).frame(height: 52)
                     .background(canSave ? AnyView(ZXGradient.ctaPurple) : AnyView(Color.zxHairlineStrong))
@@ -227,20 +237,138 @@ struct AddKnowledgePage: View {
             }.padding(.horizontal, 20).padding(.top, 8).padding(.bottom, 80) }.scrollIndicators(.hidden) }
         }
         .navigationBarTitleDisplayMode(.inline).toolbarBackground(.hidden, for: .navigationBar).animatedTabBarHide()
-        .fileImporter(isPresented: $showFilePicker, allowedContentTypes: [.plainText, .pdf, .image], allowsMultipleSelection: false) { result in
+        .fileImporter(isPresented: $showFilePicker, allowedContentTypes: [.plainText, .pdf, .image], allowsMultipleSelection: true) { result in
-            if case .success(let urls) = result, let url = urls.first { handleFile(url) }
+            if case .success(let urls) = result { handleFiles(urls) }
         }
-        .photosPicker(isPresented: $showPhotoPicker, selection: $selectedPhotoItem, matching: .images)
+        .photosPicker(isPresented: $showPhotoPicker, selection: $selectedPhotoItems, maxSelectionCount: 10, matching: .images)
-        .onChange(of: selectedPhotoItem) { _, item in
+        .onChange(of: selectedPhotoItems) { _, items in
-            guard let item else { return }
+            guard !items.isEmpty else { return }
-            Task { await handlePhoto(item) }
+            Task { await handlePhotos(items) }
         }
     }
 
-    // MARK: - Helpers
+    // MARK: - File handling
 
-    private var fileIcon: String {
+    @State private var currentUploadIndex = 0
-        let ext = selectedFileName.lowercased()
+
+    private var canSave: Bool {
+        switch sourceType {
+        case .manual: return !content.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty
+        case .file: return !selectedFiles.isEmpty && !isUploading
+        }
+    }
+
+    private func handleFiles(_ urls: [URL]) {
+        for url in urls {
+            guard url.startAccessingSecurityScopedResource() else { continue }
+            defer { url.stopAccessingSecurityScopedResource() }
+            guard let data = try? Data(contentsOf: url) else { continue }
+            let name = url.lastPathComponent
+            selectedFiles.append(SelectedFile(
+                name: name,
+                data: data,
+                icon: fileIcon(name: name),
+                size: formatSize(data.count)
+            ))
+        }
+    }
+
+    private func handlePhotos(_ items: [PhotosPickerItem]) async {
+        for item in items {
+            guard let data = try? await item.loadTransferable(type: Data.self) else { continue }
+            let compressed: Data
+            if let image = UIImage(data: data), data.count > 2 * 1024 * 1024 {
+                compressed = image.jpegData(compressionQuality: 0.6) ?? data
+            } else {
+                compressed = data
+            }
+            let name = "image_\(Int(Date().timeIntervalSince1970))_\(selectedFiles.count).jpg"
+            selectedFiles.append(SelectedFile(
+                name: name,
+                data: compressed,
+                icon: "photo",
+                size: formatSize(compressed.count)
+            ))
+        }
+        selectedPhotoItems = []
+    }
+
+    private func save() async {
+        isSaving = true
+        defer { isSaving = false }
+
+        switch sourceType {
+        case .manual:
+            do {
+                _ = try await KnowledgeItemService.shared.create(
+                    knowledgeBaseId: knowledgeBaseId,
+                    title: title.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty ? "手写笔记" : title,
+                    content: content,
+                    itemType: "manual"
+                )
+                ZXToastManager.shared.success("知识点已添加")
+                dismiss()
+            } catch {
+                ZXToastManager.shared.error("添加失败: \(error.localizedDescription)")
+            }
+
+        case .file:
+            isUploading = true
+            defer { isUploading = false }
+            var successCount = 0
+            let total = selectedFiles.count
+
+            for (i, file) in selectedFiles.enumerated() {
+                currentUploadIndex = i + 1
+                do {
+                    let mime = mimeType(name: file.name)
+                    let ext = file.name.lowercased()
+                    let itemType = ext.hasSuffix(".md") || ext.hasSuffix(".markdown") ? "markdown"
+                        : ext.hasSuffix(".txt") ? "text"
+                        : ext.hasSuffix(".pdf") ? "pdf"
+                        : ext.hasSuffix(".jpg") || ext.hasSuffix(".jpeg") || ext.hasSuffix(".png") || ext.hasSuffix(".heic") ? "image"
+                        : "file"
+
+                    let fileId: String
+                    if let image = UIImage(data: file.data) {
+                        fileId = try await FileUploadService.shared.uploadImage(image, filename: file.name)
+                    } else {
+                        fileId = try await FileUploadService.shared.uploadData(file.data, filename: file.name, mimeType: mime)
+                    }
+                    let downloadUrl = try await FileUploadService.shared.getDownloadUrl(fileId: fileId)
+
+                    // 标题：优先用户填写，否则用文件名
+                    let itemTitle: String
+                    if !title.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty {
+                        itemTitle = total == 1 ? title : "\(title) (\(i+1))"
+                    } else {
+                        itemTitle = file.name
+                    }
+
+                    _ = try await KnowledgeItemService.shared.create(
+                        knowledgeBaseId: knowledgeBaseId,
+                        title: itemTitle,
+                        content: downloadUrl,
+                        itemType: itemType
+                    )
+                    successCount += 1
+                } catch {
+                    ZXToastManager.shared.error("「\(file.name)」上传失败")
+                }
+            }
+
+            if successCount == total {
+                ZXToastManager.shared.success("\(total) 个知识点已添加")
+                dismiss()
+            } else if successCount > 0 {
+                ZXToastManager.shared.success("\(successCount)/\(total) 个知识点已添加")
+                dismiss()
+            }
+        }
+    }
+
+    private func fileIcon(name: String) -> String {
+        let ext = name.lowercased()
         if ext.hasSuffix(".md") || ext.hasSuffix(".markdown") { return "doc.richtext" }
         if ext.hasSuffix(".txt") { return "doc.plaintext" }
         if ext.hasSuffix(".pdf") { return "doc.fill" }
@@ -248,100 +376,14 @@ struct AddKnowledgePage: View {
         return "doc"
     }
 
-    private var formatFileSize: String {
+    private func formatSize(_ size: Int) -> String {
-        let size = selectedFileData?.count ?? 0
         if size < 1024 { return "\(size) B" }
         if size < 1024 * 1024 { return "\(size / 1024) KB" }
         return String(format: "%.1f MB", Double(size) / 1024 / 1024)
     }
 
-    private var canSave: Bool {
+    private func mimeType(name: String) -> String {
-        guard !title.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty else { return false }
+        let ext = name.lowercased()
-        switch sourceType {
-        case .manual: return !content.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty
-        case .file: return selectedFileData != nil && !isUploading
-        }
-    }
-
-    private func handleFile(_ url: URL) {
-        guard url.startAccessingSecurityScopedResource() else { return }
-        defer { url.stopAccessingSecurityScopedResource() }
-        guard let data = try? Data(contentsOf: url) else { return }
-        selectedFileURL = url
-        selectedFileName = url.lastPathComponent
-        selectedFileData = data
-    }
-
-    private func handlePhoto(_ item: PhotosPickerItem) async {
-        guard let data = try? await item.loadTransferable(type: Data.self),
-              let image = UIImage(data: data) else { return }
-        // 压缩大图
-        let compressed: Data
-        if data.count > 2 * 1024 * 1024 {
-            compressed = image.jpegData(compressionQuality: 0.6) ?? data
-        } else {
-            compressed = data
-        }
-        selectedFileData = compressed
-        selectedFileName = "image_\(Int(Date().timeIntervalSince1970)).jpg"
-        selectedFileURL = nil
-        selectedPhotoItem = nil
-    }
-
-    private func save() async {
-        isSaving = true
-        defer { isSaving = false }
-
-        do {
-            let finalContent: String?
-            let finalType: String?
-
-            switch sourceType {
-            case .manual:
-                finalContent = content
-                finalType = "manual"
-
-            case .file:
-                guard let data = selectedFileData else { return }
-                isUploading = true
-                defer { isUploading = false }
-
-                let mime = mimeType
-                let fileId: String
-                if let image = UIImage(data: data) {
-                    fileId = try await FileUploadService.shared.uploadImage(image, filename: selectedFileName)
-                } else {
-                    fileId = try await FileUploadService.shared.uploadData(data, filename: selectedFileName, mimeType: mime)
-                }
-                let downloadUrl = try await FileUploadService.shared.getDownloadUrl(fileId: fileId)
-                finalContent = downloadUrl
-                finalType = fileType
-            }
-
-            _ = try await KnowledgeItemService.shared.create(
-                knowledgeBaseId: knowledgeBaseId,
-                title: title,
-                content: finalContent,
-                itemType: finalType
-            )
-            ZXToastManager.shared.success("知识点已添加")
-            dismiss()
-        } catch {
-            ZXToastManager.shared.error("添加失败: \(error.localizedDescription)")
-        }
-    }
-
-    private var fileType: String {
-        let ext = selectedFileName.lowercased()
-        if ext.hasSuffix(".md") || ext.hasSuffix(".markdown") { return "markdown" }
-        if ext.hasSuffix(".txt") { return "text" }
-        if ext.hasSuffix(".pdf") { return "pdf" }
-        if ext.hasSuffix(".jpg") || ext.hasSuffix(".jpeg") || ext.hasSuffix(".png") || ext.hasSuffix(".heic") { return "image" }
-        return "file"
-    }
-
-    private var mimeType: String {
-        let ext = selectedFileName.lowercased()
         if ext.hasSuffix(".md") || ext.hasSuffix(".markdown") { return "text/markdown" }
         if ext.hasSuffix(".txt") { return "text/plain" }
         if ext.hasSuffix(".pdf") { return "application/pdf" }