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/ReaderController/RDEPUBReaderAnnotationCoordinator.swift

@@ -24,6 +24,10 @@ final class RDEPUBReaderAnnotationCoordinator {
     func updateCurrentSelection(_ selection: RDEPUBSelection?) {
         guard let controller else { return }
         controller.currentSelection = selection?.isEmpty == false ? selection : nil
+        if controller.currentSelection != nil,
+           controller.readerView.isShowToolView == false {
+            controller.readerView.tapCenter()
+        }
         controller.bottomToolView.setAddHighlightEnabled(
             controller.configuration.allowsHighlights && controller.currentSelection != nil
         )
@@ -329,8 +333,9 @@ final class RDEPUBReaderAnnotationCoordinator {
 
     private func persistHighlightsAndRefreshContent() {
         guard let controller else { return }
-        guard let currentBookIdentifier = controller.currentBookIdentifier else { return }
-        controller.persistence?.saveHighlights(controller.activeHighlights, for: currentBookIdentifier)
+        if let currentBookIdentifier = controller.currentBookIdentifier {
+            controller.persistence?.saveHighlights(controller.activeHighlights, for: currentBookIdentifier)
+        }
         controller.delegate?.epubReader(controller, didUpdateHighlights: controller.activeHighlights)
         controller.updateReaderChrome()
         controller.refreshVisibleContentPreservingLocation()

Sources/RDReaderView/EPUBUI/ReaderController/RDEPUBReaderChromeCoordinator.swift

@@ -14,7 +14,6 @@ final class RDEPUBReaderChromeCoordinator {
     func makeTopToolView() -> RDEPUBReaderTopToolView {
         let toolView = RDEPUBReaderTopToolView()
         toolView.onBack = { [weak self] in
-            print("[Debug] onBack fired, controller: \(String(describing: self?.controller))")
             self?.handleBackAction()
         }
         toolView.onToggleBookmark = { [weak self] in
@@ -81,6 +80,9 @@ final class RDEPUBReaderChromeCoordinator {
         settingsController.onFontSizeChange = { [weak controller] fontSize in
             controller?.updateConfiguration { $0.fontSize = fontSize }
         }
+        settingsController.onFontChoiceChange = { [weak controller] fontChoice in
+            controller?.updateConfiguration { $0.fontChoice = fontChoice }
+        }
         settingsController.onLineHeightChange = { [weak controller] lineHeightMultiple in
             controller?.updateConfiguration { $0.lineHeightMultiple = lineHeightMultiple }
         }

Sources/RDReaderView/EPUBUI/ReaderController/RDEPUBReaderContext.swift

@@ -82,7 +82,7 @@ final class RDEPUBReaderContext {
     }
 
     func currentTextRenderStyle() -> RDEPUBTextRenderStyle {
-        let font = UIFont.systemFont(ofSize: configuration.fontSize)
+        let font = configuration.fontChoice.font(ofSize: configuration.fontSize)
         let lineSpacing = max(font.lineHeight * (configuration.lineHeightMultiple - 1), 4)
         return RDEPUBTextRenderStyle(
             font: font,