refactor: rename RDReaderView -> RDEpubReaderView, update pod config and docs

- Rename source module from RDReaderView to RDEpubReaderView
- Move all source files from Sources/RDReaderView/ to Sources/RDEpubReaderView/
- Update podspec: RDReaderView.podspec -> RDEpubReaderView.podspec
- Update Podfile, demo project, and CocoaPods config for new pod name
- Delete old RDReaderView pod support files from ReadViewDemo/Pods
- Add new RDEpubReaderView pod support files
- Update documentation (API ref, architecture, UML, conventions, etc.)
- Add FixedLayoutRotationTests
- Update .gitignore: exclude .DS_Store, manual unpack backups, _ssoft-output

Sources/RDEpubReaderView/EPUBUI/RDEPUBReaderController+Trial.swift

@@ -0,0 +1,86 @@
+import UIKit
+
+/// 试读墙支持。
+///
+/// 设计：`pageCountOfReaderView` 仍返回原始内容页数（内容页显示的总页数不受影响），
+/// 仅 `numberOfPages(in:)` 在启用试读墙时 +1；试读墙页固定位于最后一个可读页之后。
+/// 两种形态统一覆盖：
+///   - readoor 独立试读 epub（整本都是试读章节）：readableChapterCount 传 nil，墙追加在全书末尾；
+///   - 整本 epub + 按章限制：readableChapterCount 传 N，超出章节页不展示（仅 bookPageMap 路径）。
+extension RDEPUBReaderController {
+
+    /// 试读墙视图（首次访问经 delegate 获取并缓存）
+    var trialWallView: UIView? {
+        if let cached = cachedTrialWallView {
+            return cached
+        }
+        guard configuration.trialPolicy != nil else { return nil }
+        let view = delegate?.epubReaderTrialWallView(self)
+        cachedTrialWallView = view
+        return view
+    }
+
+    /// 是否启用试读墙：配置了试读策略且宿主提供了墙视图
+    var isTrialWallEnabled: Bool {
+        configuration.trialPolicy != nil && trialWallView != nil
+    }
+
+    /// 原始可读内容页数（不含试读墙页）。
+    /// readableChapterCount 指定且存在 bookPageMap 时按章截断，否则为全部内容页。
+    var readableContentPageCount: Int {
+        let rawCount = pageCountOfReaderView(readerView: readerView)
+        guard let policy = configuration.trialPolicy,
+              let readableChapterCount = policy.readableChapterCount,
+              readableChapterCount > 0,
+              let pageMap = readerContext.bookPageMap else {
+            return rawCount
+        }
+        // 第一个不可读章节（spineIndex >= readableChapterCount）的起始绝对页 = 可读页数
+        let firstLockedStart = pageMap.entries
+            .first { $0.spineIndex >= readableChapterCount }?
+            .absolutePageStart
+        return firstLockedStart ?? rawCount
+    }
+
+    /// 试读墙页的绝对索引（0-based）；未启用时为 nil
+    var trialWallPageIndex: Int? {
+        guard isTrialWallEnabled else { return nil }
+        return readableContentPageCount
+    }
+
+    /// 供 RDEpubReaderView 使用的有效页数：启用试读墙时为可读页数 + 1（墙页）
+    var effectiveNumberOfPages: Int {
+        guard isTrialWallEnabled else {
+            return pageCountOfReaderView(readerView: readerView)
+        }
+        return readableContentPageCount + 1
+    }
+
+    /// 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()
+        container.setWallView(trialWallView)
+        return container
+    }
+}
+
+/// 试读墙页容器：让宿主墙视图铺满整页
+final class RDEPUBTrialWallContainerView: UIView {
+
+    private weak var wallView: UIView?
+
+    func setWallView(_ view: UIView?) {
+        guard wallView !== view else { return }
+        wallView?.removeFromSuperview()
+        guard let view else { return }
+        view.translatesAutoresizingMaskIntoConstraints = false
+        addSubview(view)
+        NSLayoutConstraint.activate([
+            view.leadingAnchor.constraint(equalTo: leadingAnchor),
+            view.trailingAnchor.constraint(equalTo: trailingAnchor),
+            view.topAnchor.constraint(equalTo: topAnchor),
+            view.bottomAnchor.constraint(equalTo: bottomAnchor)
+        ])
+        wallView = view
+    }
+}