feat(reader): 实现大书快速进入与增量分页路径

- PaginationCoordinator: 新增 textReflowable 快速进入路径，支持增量章节构建
  与 staged 合并策略，避免整书一次性构建的主线程阻塞
- TextBookBuilder: 重构为支持单章构建与增量合并模式
- ChapterPageCounter: 优化分页计数逻辑，支持章节级分页缓存
- PageFrameFactory: 新增 CoreText 页面帧工厂，提升排版性能
- ReaderContext/ReaderRuntime: 适配增量分页状态管理

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

Sources/RDReaderView/EPUBUI/RDEPUBReaderHighlightsViewController.swift

@@ -247,6 +247,8 @@ final class RDEPUBReaderBookmarksViewController: UITableViewController {
 
     override func viewDidLoad() {
         super.viewDidLoad()
+        view.accessibilityIdentifier = "epub.reader.bookmarks.panel"
+        tableView.accessibilityIdentifier = "epub.reader.bookmarks.table"
         tableView.tableFooterView = UIView(frame: .zero)
         tableView.separatorInset = UIEdgeInsets(top: 0, left: 16, bottom: 0, right: 16)
         applyTheme()
@@ -286,6 +288,7 @@ final class RDEPUBReaderBookmarksViewController: UITableViewController {
         navigationController?.navigationBar.tintColor = theme.toolControlTextColor
         navigationController?.navigationBar.barTintColor = theme.toolBackgroundColor
         navigationController?.navigationBar.titleTextAttributes = [.foregroundColor: theme.toolControlTextColor]
+        navigationController?.navigationBar.accessibilityIdentifier = "epub.reader.bookmarks.navbar"
     }
 
     private func updateEmptyState() {