feat: unify reader chrome state management

- Add RDEPUBReaderUIState struct for centralized UI state model
- Refactor RDEPUBReaderChromeCoordinator with makeUIState() and applyUIState()
- Remove direct UI updates from RDEPUBReaderAnnotationCoordinator
- Consolidate updateBookmarkChrome() into updateReaderChrome()
- Update RDEPUBReaderContext, Runtime, and LocationCoordinator
- Add reader problem fix development checklist documentation

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Sources/RDReaderView/EPUBUI/TextPage/RDEPUBTextContentView.swift

@@ -40,6 +40,8 @@ final class RDEPUBTextContentView: UIView, UIGestureRecognizerDelegate {
         let view = RDEPUBTextPageRenderView()
         view.backgroundColor = .clear
         view.isOpaque = false
+        view.isAccessibilityElement = true
+        view.accessibilityTraits = .staticText
         return view
     }()
 
@@ -118,6 +120,7 @@ final class RDEPUBTextContentView: UIView, UIGestureRecognizerDelegate {
             } else {
                 self.hideSelectionMenu()
             }
+            self.updateAccessibilityDecorationSummary()
             self.delegate?.textContentView(self, didChangeSelection: selection)
         }
         selectionController.pageProvider = { [weak self] in self?.currentPage }
@@ -250,6 +253,7 @@ final class RDEPUBTextContentView: UIView, UIGestureRecognizerDelegate {
         backgroundOverlayView.applyDecorations(bgDecorations)
         overlayView.applyDecorations(fgDecorations)
 #endif
+        updateAccessibilityDecorationSummary()
 
         delegate?.textContentView(self, didChangeSelection: nil)
         setNeedsLayout()
@@ -262,6 +266,7 @@ final class RDEPUBTextContentView: UIView, UIGestureRecognizerDelegate {
         selectionController.clearSelection(renderView: coreTextRenderView)
         overlayView.clearSelection()
         backgroundOverlayView.clearSelection()
+        updateAccessibilityDecorationSummary()
         UIMenuController.shared.setMenuVisible(false, animated: true)
     }
 
@@ -570,13 +575,21 @@ final class RDEPUBTextContentView: UIView, UIGestureRecognizerDelegate {
 #endif
     }
 
+    private func updateAccessibilityDecorationSummary() {
+#if canImport(DTCoreText)
+        coreTextContentView.accessibilityValue = [
+            backgroundOverlayView.decorationSummary(),
+            overlayView.decorationSummary()
+        ].joined(separator: " | ")
+#endif
+    }
+
     private func highlight(at point: CGPoint) -> RDEPUBHighlight? {
         guard let page = currentPage else { return nil }
         let absoluteRange = backgroundOverlayView.absoluteRange(at: point) ?? overlayView.absoluteRange(at: point)
         guard let absoluteRange else { return nil }
         let matches = currentHighlights.filter { highlight in
-            guard highlight.location.href == page.href,
-                  let range = RDEPUBTextOffsetRangeInfo.decode(from: highlight.rangeInfo)?.nsRange else {
+            guard let range = RDEPUBTextOffsetRangeInfo.decode(from: highlight.rangeInfo)?.nsRange else {
                 return false
             }
             return NSIntersectionRange(range, absoluteRange).length > 0