feat: add in-reader search and restructure documentation

- Add RDEPUBReaderSearchBarView with animated show/hide, keyword
  navigation, and match counting integrated into the reader controller
- Restructure docs: replace scattered design docs with consolidated
  BUSINESS_LOGIC.md and UML_CLASS_DIAGRAMS.md; update ARCHITECTURE.md
- Add SearchTests and FanrenParseTimeTest; enhance LargeBookOnDemandTests
- Add scripts/run_ui_regression.sh and summarize_ui_results.py for
  automated UI test execution and reporting

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

Sources/RDReaderView/EPUBUI/RDEPUBReaderController.swift

@@ -155,6 +155,9 @@ public final class RDEPUBReaderController: UIViewController {
     }
     lazy var topToolView = runtime.makeTopToolView()
     lazy var bottomToolView = runtime.makeBottomToolView()
+    lazy var searchBarView = RDEPUBReaderSearchBarView()
+    /// 搜索栏是否当前可见
+    private(set) var isSearchBarVisible = false
     var currentBookIdentifier: String? {
         get { readerContext.currentBookIdentifier }
         set { readerContext.currentBookIdentifier = newValue }
@@ -273,6 +276,9 @@ public final class RDEPUBReaderController: UIViewController {
         currentBrightness = currentBrightness
         readerAssemblyCoordinator.assembleInterface()
         readerAssemblyCoordinator.finishExternalTextBookLaunchIfNeeded()
+        readerView.onToolViewVisibilityChanged = { [weak self] isVisible in
+            self?.handleToolViewVisibilityChanged(isVisible: isVisible)
+        }
     }
 
     public override func viewWillAppear(_ animated: Bool) {
@@ -302,4 +308,100 @@ public final class RDEPUBReaderController: UIViewController {
         runtime.viewportMonitor.viewWillTransition(with: coordinator)
     }
 
+    // MARK: - 搜索栏管理
+
+    /// 显示搜索栏，将其添加到 readerView 并滑入动画
+    func showSearchBar() {
+        guard !isSearchBarVisible else { return }
+        isSearchBarVisible = true
+        searchBarView.apply(theme: configuration.theme)
+
+        readerView.addSubview(searchBarView)
+        readerView.searchBarView = searchBarView
+        let topToolbarHeight: CGFloat = readerView.safeAreaInsets.top + 52
+        NSLayoutConstraint.activate([
+            searchBarView.leadingAnchor.constraint(equalTo: readerView.leadingAnchor),
+            searchBarView.trailingAnchor.constraint(equalTo: readerView.trailingAnchor),
+            searchBarView.topAnchor.constraint(equalTo: readerView.topAnchor, constant: topToolbarHeight),
+            searchBarView.heightAnchor.constraint(equalToConstant: 52)
+        ])
+
+        searchBarView.transform = CGAffineTransform(translationX: 0, y: -52)
+        UIView.animate(withDuration: 0.3) {
+            self.searchBarView.transform = .identity
+        }
+
+        searchBarView.onSearchSubmit = { [weak self] keyword in
+            self?.runtime.search(keyword: keyword)
+            self?.updateSearchCount()
+        }
+        searchBarView.onSearchPrevious = { [weak self] in
+            _ = self?.runtime.searchPrevious()
+            self?.updateSearchCount()
+        }
+        searchBarView.onSearchNext = { [weak self] in
+            _ = self?.runtime.searchNext()
+            self?.updateSearchCount()
+        }
+        searchBarView.onClose = { [weak self] in
+            self?.hideSearchBar(clearSearch: true)
+        }
+
+        if let keyword = searchState?.keyword, !keyword.isEmpty {
+            searchBarView.restoreKeyword(keyword)
+            updateSearchCount()
+        }
+
+        // 延迟到下一帧确保视图已布局后再获取焦点
+        DispatchQueue.main.async { [weak self] in
+            self?.searchBarView.textField.becomeFirstResponder()
+        }
+    }
+
+    /// 隐藏搜索栏，带动画滑出
+    /// - Parameter clearSearch: 是否同时清除搜索状态
+    func hideSearchBar(clearSearch: Bool = false) {
+        guard isSearchBarVisible else { return }
+        isSearchBarVisible = false
+
+        searchBarView.textField.resignFirstResponder()
+        UIView.animate(withDuration: 0.3, animations: {
+            self.searchBarView.transform = CGAffineTransform(translationX: 0, y: -52)
+        }) { _ in
+            self.searchBarView.removeFromSuperview()
+            self.searchBarView.transform = .identity
+            self.readerView.searchBarView = nil
+        }
+
+        if clearSearch {
+            runtime.clearSearch()
+        }
+    }
+
+    /// 同步搜索栏匹配计数
+    private func updateSearchCount() {
+        guard let searchState else {
+            searchBarView.showNoResults()
+            return
+        }
+        if let index = searchState.currentMatchIndex {
+            searchBarView.updateMatchCount(current: index + 1, total: searchState.matches.count)
+        } else if searchState.matches.isEmpty {
+            searchBarView.showNoResults()
+        }
+    }
+
+    /// 当工具栏可见性变化时同步搜索栏（由 RDReaderView 回调调用）
+    func handleToolViewVisibilityChanged(isVisible: Bool) {
+        if isVisible {
+            if searchState != nil && !isSearchBarVisible {
+                showSearchBar()
+            }
+        } else {
+            if isSearchBarVisible {
+                hideSearchBar(clearSearch: false)
+            }
+        }
+    }
+
 }