feat(reader): 增强阅读器功能与 UI 测试支持

- 新增字体选择（系统/宋体/圆体/等宽）与暗色图片柔化配置
- 文本选择改为自定义手势+操作栏（拷贝/高亮/批注）
- 添加 accessibilityIdentifier 支持自动化 UI 测试
- 新增 UITests 覆盖阅读器打开/关闭、工具栏、设置面板、批注等
- 添加 Demo 测试用 EPUB 书源（宝山辽墓材料与释读）
- 新增文档：UI 自动化测试、功能开发计划、阅读器规划

Sources/RDReaderView/ReaderView/RDReaderContentCell.swift

@@ -48,6 +48,7 @@ class RDReaderContentCell: UICollectionViewCell {
 
     override init(frame: CGRect) {
         super.init(frame: frame)
+        accessibilityIdentifier = "epub.reader.content.cell"
     }
     required init?(coder: NSCoder) {
         fatalError("init(coder:) has not been implemented")

Sources/RDReaderView/ReaderView/RDReaderView+ToolView.swift

@@ -6,7 +6,6 @@ extension RDReaderView {
     /// 点击屏幕中央区域，切换工具栏的显示/隐藏
     func tapCenter() {
         refreshToolViewsFromProviderIfNeeded()
-        print("[Debug] tapCenter called, isShowToolView was: \(isShowToolView), topToolView: \(String(describing: topToolView)), onBack: \(String(describing: (topToolView as? RDEPUBReaderTopToolView)?.onBack))")
         isShowToolView = !isShowToolView
         if isShowToolView {
             if let topToolView = topToolView {

Sources/RDReaderView/ReaderView/RDReaderView.swift

@@ -74,6 +74,7 @@ public class RDReaderView: UIView {
 
         let collectionView = UICollectionView(frame: .zero, collectionViewLayout: layout)
         collectionView.backgroundColor = UIColor.clear
+        collectionView.accessibilityIdentifier = "epub.reader.paging"
         return collectionView
     }()
     private let spreadResolver = RDReaderSpreadResolver()
@@ -327,6 +328,8 @@ public class RDReaderView: UIView {
 
     override init(frame: CGRect) {
         super.init(frame: frame)
+        accessibilityIdentifier = "epub.reader.content"
+        isAccessibilityElement = false
     }
 
     /// 布局子视图时调用
@@ -610,7 +613,6 @@ public class RDReaderView: UIView {
         let point = tap.location(in: tap.view)
         if isShowToolView {
             let hitView = hitTest(point, with: nil)
-            print("[Debug] tapAction: isShowToolView=true, point=\(point), hitView=\(String(describing: hitView)), top=\(String(describing: topToolView))")
             if let top = topToolView, isHitView(hitView, inside: top, point: point) { return }
             if let bottom = bottomToolView, isHitView(hitView, inside: bottom, point: point) { return }
         }