feat: complete large-book pagination runtime and UI coverage

Sources/RDReaderView/EPUBUI/RDEPUBReaderController+DataSource.swift

@@ -15,11 +15,28 @@ import UIKit
 extension RDEPUBReaderController: RDReaderDataSource, RDReaderDelegate {
     /// 返回阅读器总页数
     public func pageCountOfReaderView(readerView: RDReaderView) -> Int {
-        textBook?.pages.count ?? activePages.count
+        readerContext.bookPageMap?.totalPages ?? textBook?.pages.count ?? activePages.count
     }
 
     /// 为指定页码创建或复用内容视图（优先文本渲染，回退 Web 渲染）
     public func pageContentView(readerView: RDReaderView, pageNum: Int, containerView: UIView?) -> UIView {
+        if readerContext.bookPageMap != nil {
+            _ = runtime.prepareOnDemandChapter(forAbsolutePageNumber: pageNum + 1)
+            if let resolvedPage = runtime.pageResolver.resolvePage(absolutePageIndex: pageNum) {
+                let contentView = (containerView as? RDEPUBTextContentView) ?? RDEPUBTextContentView()
+                contentView.delegate = self
+                contentView.configure(
+                    page: resolvedPage.page,
+                    pageNumber: pageNum + 1,
+                    totalPages: pageCountOfReaderView(readerView: readerView),
+                    configuration: configuration,
+                    highlights: textHighlights(for: resolvedPage.page),
+                    searchState: searchState
+                )
+                return contentView
+            }
+        }
+
         if let textBook, let page = textBook.page(at: pageNum + 1) {
             let contentView = (containerView as? RDEPUBTextContentView) ?? RDEPUBTextContentView()
             contentView.delegate = self
@@ -53,7 +70,7 @@ extension RDEPUBReaderController: RDReaderDataSource, RDReaderDelegate {
 
     /// 返回页面内容视图的重用标识符（区分文本与 Web 渲染）
     public func pageIdentifier(readerView: RDReaderView, pageNum: Int) -> String? {
-        textBook == nil
+        (textBook == nil && readerContext.bookPageMap == nil)
             ? NSStringFromClass(RDEPUBWebContentView.self)
             : NSStringFromClass(RDEPUBTextContentView.self)
     }
@@ -94,13 +111,17 @@ extension RDEPUBReaderController: RDReaderDataSource, RDReaderDelegate {
         readerContext.markUserNavigationActivity()
         updateCurrentSelection(nil)
         reconcileTextPaginationSizeIfNeeded(for: pageNum)
+        if readerContext.bookPageMap != nil {
+            _ = runtime.prepareOnDemandChapter(forAbsolutePageNumber: pageNum + 1)
+            runtime.extendPartialBookPageMapIfNeeded(currentPageNumber: pageNum + 1)
+        }
 
         let totalPages = pageCountOfReaderView(readerView: readerView)
         if totalPages > 0, pageNum == totalPages - 1 {
             delegate?.epubReaderDidReachEnd(self)
         }
 
-        if textBook != nil,
+        if (textBook != nil || readerContext.bookPageMap != nil),
            let location = resolvedTextLocation(forPageNumber: pageNum + 1) {
             persist(location: location)
             synchronizeTextReadingState(pageNumber: pageNum + 1, location: location)
@@ -123,7 +144,7 @@ extension RDEPUBReaderController: RDReaderDataSource, RDReaderDelegate {
 
     /// 检测页面尺寸变化并触发重新分页（避免布局错乱）
     private func reconcileTextPaginationSizeIfNeeded(for pageNum: Int) {
-        guard textBook != nil,
+        guard textBook != nil || readerContext.bookPageMap != nil,
               !isRepaginating,
               !isReconcilingTextPaginationSize,
               pageNum >= 0,
@@ -147,7 +168,7 @@ extension RDEPUBReaderController: RDReaderDataSource, RDReaderDelegate {
         DispatchQueue.main.async { [weak self] in
             guard let self else { return }
             self.isReconcilingTextPaginationSize = false
-            guard self.textBook != nil, !self.isRepaginating else { return }
+            guard (self.textBook != nil || self.readerContext.bookPageMap != nil), !self.isRepaginating else { return }
             self.repaginatePreservingCurrentLocation()
         }
     }