feat: 支持 EPUB 阅读并改善规则兼容与阅读稳定性

支持 EPUB 2/3 导入、目录、封面和章节插图，保留本地书管理与阅读进度。
修复 JSON 模板、动态替换与请求参数兼容，以及 RSS 翻页和连续滚动定位。
更新编辑器工具栏和回归测试，发布版本为 0.1.12（build 18）。

App/Features/Books/BookLibraryModel.swift

@@ -360,7 +360,7 @@ final class BookLibraryModel: ObservableObject {
 
     func addLocalFile(at url: URL) async throws {
         guard !books.contains(where: { $0.bookUrl == url.absoluteString }) else { return }
-        let report = try await Task.detached { [localService] in try localService.openTextFile(at: url) }.value
+        let report = try await Task.detached { [localService] in try localService.openFile(at: url) }.value
         guard !books.contains(where: { $0.bookUrl == url.absoluteString }) else { return }
         guard await persist(books + [report.book]) else {
             throw LocalFileError.saveFailed(errorMessage ?? "无法写入数据库")

App/Features/Books/LocalBookDetailView.swift

@@ -33,16 +33,20 @@ struct LocalBookDetailView: View {
         ScrollView {
             VStack(spacing: 16) {
                 VStack(spacing: 14) {
-                    BookCoverArtwork(title: book.name, author: book.author, width: 108, height: 154)
+                    BookCoverArtwork(title: book.name, author: book.author, remoteURL: book.customCoverUrl ?? book.coverUrl, width: 108, height: 154)
                     Text(book.name).font(.title2.bold())
+                    if !book.author.isEmpty { Text(book.author).font(.subheadline).foregroundStyle(.secondary) }
                     HStack {
-                        StatusPill(text: "本地 TXT", systemImage: "doc.text.fill")
+                        StatusPill(text: "本地 " + (URL(string: book.bookUrl)?.pathExtension.uppercased() ?? "TXT"), systemImage: "doc.text.fill")
                         if let charset = book.charset { StatusPill(text: charset, color: ReadingTheme.coral, systemImage: "character") }
                     }
                     Text(book.originName).font(.caption).foregroundStyle(.secondary)
                 }
                 .padding(.top, 12)
 
+                if let intro = book.intro, !intro.isEmpty {
+                    ReadingCard { Text(intro).font(.subheadline).frame(maxWidth: .infinity, alignment: .leading) }
+                }
                 ReadingCard {
                     VStack(alignment: .leading, spacing: 0) {
                         HStack {

App/Features/Books/SourceSwitchView.swift

@@ -151,6 +151,6 @@ struct SourceSwitchView: View {
             .padding(.vertical, 5)
         }
         .disabled(model.switchingID != nil)
-        .accessibilityIdentifier("sourceSwitch.candidate.\(candidate.book.origin)")
+        .accessibilityIdentifier("sourceSwitch.candidate.\(candidate.id)")
     }
 }