fix epub reader playback and trial navigation

Sources/RDEpubReaderView/EPUBUI/RDEPUBReaderController+Trial.swift

@@ -56,6 +56,17 @@ extension RDEPUBReaderController {
         return readableContentPageCount + 1
     }
 
+    func isReadableTableOfContentsLocation(_ location: RDEPUBLocation) -> Bool {
+        guard let policy = configuration.trialPolicy,
+              let readableChapterCount = policy.readableChapterCount else {
+            return true
+        }
+        guard let spineIndex = readerContext.normalizedSpineIndex(for: location) else {
+            return true
+        }
+        return spineIndex < readableChapterCount
+    }
+
     /// 构建试读墙页承载视图（铺满一页，居中放置宿主提供的墙视图）
     func makeTrialWallPageView(reusableView: UIView?) -> UIView {
         let container = (reusableView as? RDEPUBTrialWallContainerView) ?? RDEPUBTrialWallContainerView()
@@ -65,12 +76,19 @@ extension RDEPUBReaderController {
 }
 
 /// 试读墙页容器：让宿主墙视图铺满整页
-final class RDEPUBTrialWallContainerView: UIView {
+final class RDEPUBTrialWallContainerView: UIView, RDEpubReaderCachePolicyProviding {
+
+    /// 宿主只提供一份试读墙 View。预加载会同时构建多个页容器，若缓存该容器会
+    /// 把同一 View 从实际可见页移走，最终表现为横竖翻页的试读墙白屏。
+    var shouldAvoidReaderPageCaching: Bool { true }
 
     private weak var wallView: UIView?
 
     func setWallView(_ view: UIView?) {
-        guard wallView !== view else { return }
+        // 即使 View 对象相同，只要它已被其他复用容器接管，也必须重新挂回当前页。
+        if wallView === view, view?.superview === self {
+            return
+        }
         wallView?.removeFromSuperview()
         guard let view else { return }
         view.translatesAutoresizingMaskIntoConstraints = false