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/EPUBUI/RDURLReaderController.swift

@@ -31,6 +31,16 @@ public final class RDURLReaderController: UIViewController {
     private let epubConfiguration: RDEPUBReaderConfiguration
     /// 内嵌的阅读器控制器
     private var embeddedController: UIViewController?
+    private let demoStateLabel: UILabel = {
+        let label = UILabel()
+        label.accessibilityIdentifier = "demo.reader.state"
+        label.font = .systemFont(ofSize: 1)
+        label.textColor = .clear
+        label.alpha = 0.01
+        label.isAccessibilityElement = true
+        label.text = "reader=opening"
+        return label
+    }()
 
     /// 初始化方法
     /// - Parameters:
@@ -56,13 +66,19 @@ public final class RDURLReaderController: UIViewController {
         view.backgroundColor = .systemBackground
         title = bookURL.deletingPathExtension().lastPathComponent
         embedReaderController()
+        installDemoStateLabel()
+    }
+
+    public override func viewDidAppear(_ animated: Bool) {
+        super.viewDidAppear(animated)
+        emitDemoState()
     }
 
     /// 切换阅读器的翻页模式（Demo 用）
     /// - Parameter displayType: 目标翻页模式
     public func applyDemoDisplayType(_ displayType: RDReaderView.DisplayType) {
         readerController?.configuration.displayType = displayType
-        logDemoState(prefix: "display=\(displayType.demoArgumentValue)")
+        emitDemoState(prefix: "display=\(displayType.demoArgumentValue)")
     }
 
     /// 跳转到指定页码（Demo 用）
@@ -74,7 +90,7 @@ public final class RDURLReaderController: UIViewController {
     public func goToDemoPage(_ pageNumber: Int, animated: Bool = false) -> Bool {
         let moved = readerController?.go(toPageNumber: pageNumber, animated: animated) ?? false
         if moved {
-            logDemoState(prefix: "page=\(pageNumber)")
+            emitDemoState(prefix: "page=\(pageNumber)")
         }
         return moved
     }
@@ -162,6 +178,8 @@ public final class RDURLReaderController: UIViewController {
             controller.view.bottomAnchor.constraint(equalTo: view.bottomAnchor),
         ])
         controller.didMove(toParent: self)
+        readerController?.delegate = self
+        emitDemoState()
     }
 
     /// 获取内嵌的 EPUB 阅读器控制器（如果存在）
@@ -179,6 +197,32 @@ public final class RDURLReaderController: UIViewController {
         print("[ReadViewDemo] automation \(prefix) -> page \(page) href \(href) progression \(progression)")
     }
 
+    private func installDemoStateLabel() {
+        view.addSubview(demoStateLabel)
+        demoStateLabel.translatesAutoresizingMaskIntoConstraints = false
+        NSLayoutConstraint.activate([
+            demoStateLabel.leadingAnchor.constraint(equalTo: view.leadingAnchor),
+            demoStateLabel.topAnchor.constraint(equalTo: view.topAnchor),
+            demoStateLabel.widthAnchor.constraint(equalToConstant: 1),
+            demoStateLabel.heightAnchor.constraint(equalToConstant: 1)
+        ])
+    }
+
+    private func emitDemoState(prefix: String? = nil) {
+        let page = readerController?.currentPageNumber.map(String.init) ?? "nil"
+        let display = readerController?.configuration.displayType.demoArgumentValue ?? epubConfiguration.displayType.demoArgumentValue
+        let toolbar = readerController?.readerView.isShowToolView == true ? "visible" : "hidden"
+        let highlights = readerController?.highlights.count ?? 0
+        let selection = readerController?.currentSelection == nil ? 0 : 1
+        let state = "reader=opened page=\(page) display=\(display) toolbar=\(toolbar) highlights=\(highlights) selection=\(selection)"
+        demoStateLabel.text = state
+        if let prefix {
+            logDemoState(prefix: prefix)
+        } else {
+            print("[ReadViewDemo] automation \(state)")
+        }
+    }
+
     /// 计算文本分页的页面尺寸。
     /// 分页器使用完整 viewport，真实可绘制区域由 layoutConfig.edgeInsets 控制，
     /// 以保持与页面展示时的内容几何一致。
@@ -188,7 +232,7 @@ public final class RDURLReaderController: UIViewController {
 
     /// 根据当前配置生成文本渲染样式
     private func currentTextRenderStyle() -> RDEPUBTextRenderStyle {
-        let font = UIFont.systemFont(ofSize: epubConfiguration.fontSize)
+        let font = epubConfiguration.fontChoice.font(ofSize: epubConfiguration.fontSize)
         let lineSpacing = max(font.lineHeight * (epubConfiguration.lineHeightMultiple - 1), 4)
         return RDEPUBTextRenderStyle(
             font: font,
@@ -214,6 +258,20 @@ public final class RDURLReaderController: UIViewController {
     }
 }
 
+extension RDURLReaderController: RDEPUBReaderDelegate {
+    public func epubReader(_ reader: UIViewController, didUpdateLocation location: RDEPUBLocation) {
+        emitDemoState()
+    }
+
+    public func epubReader(_ reader: UIViewController, didChangeSelection selection: RDEPUBSelection?) {
+        emitDemoState(prefix: "selection=\(selection == nil ? 0 : 1)")
+    }
+
+    public func epubReader(_ reader: UIViewController, didUpdateHighlights highlights: [RDEPUBHighlight]) {
+        emitDemoState(prefix: "highlights=\(highlights.count)")
+    }
+}
+
 /// 翻页模式扩展：提供 Demo 命令行参数值
 private extension RDReaderView.DisplayType {
     /// 返回翻页模式对应的 Demo 命令行参数字符串