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/RDEPUBReaderTopToolView.swift

@@ -10,8 +10,11 @@ public final class RDEPUBReaderTopToolView: RDEPUBReaderToolView {
     var onBack: (() -> Void)?
     /// 书签按钮点击回调
     var onToggleBookmark: (() -> Void)?
+    /// 搜索按钮点击回调
+    var onSearch: (() -> Void)?
 
     private let backButton = RDEPUBReaderTintButton(type: .system)
+    private let searchButton = RDEPUBReaderTintButton(type: .system)
     private let bookmarkButton = RDEPUBReaderTintButton(type: .system)
     private let titleLabel: UILabel = {
         let label = UILabel()
@@ -27,14 +30,17 @@ public final class RDEPUBReaderTopToolView: RDEPUBReaderToolView {
         accessibilityIdentifier = "epub.reader.topToolbar"
         self.backgroundColor = .white
         addSubview(backButton)
+        addSubview(searchButton)
         addSubview(bookmarkButton)
         addSubview(titleLabel)
 
         backButton.translatesAutoresizingMaskIntoConstraints = false
+        searchButton.translatesAutoresizingMaskIntoConstraints = false
         bookmarkButton.translatesAutoresizingMaskIntoConstraints = false
         titleLabel.translatesAutoresizingMaskIntoConstraints = false
 
         backButton.addTarget(self, action: #selector(backAction), for: .touchUpInside)
+        searchButton.addTarget(self, action: #selector(searchAction), for: .touchUpInside)
         bookmarkButton.addTarget(self, action: #selector(bookmarkAction), for: .touchUpInside)
 
         NSLayoutConstraint.activate([
@@ -50,17 +56,26 @@ public final class RDEPUBReaderTopToolView: RDEPUBReaderToolView {
             bookmarkButton.widthAnchor.constraint(equalToConstant: 44),
             bookmarkButton.heightAnchor.constraint(equalToConstant: 44),
 
+            searchButton.trailingAnchor.constraint(equalTo: bookmarkButton.leadingAnchor, constant: -4),
+            searchButton.topAnchor.constraint(equalTo: safeAreaLayoutGuide.topAnchor, constant: 4),
+            searchButton.bottomAnchor.constraint(equalTo: bottomAnchor, constant: -4),
+            searchButton.widthAnchor.constraint(equalToConstant: 44),
+            searchButton.heightAnchor.constraint(equalToConstant: 44),
+
             titleLabel.leadingAnchor.constraint(equalTo: backButton.trailingAnchor, constant: 8),
-            titleLabel.trailingAnchor.constraint(equalTo: bookmarkButton.leadingAnchor, constant: -8),
+            titleLabel.trailingAnchor.constraint(equalTo: searchButton.leadingAnchor, constant: -8),
             titleLabel.centerYAnchor.constraint(equalTo: backButton.centerYAnchor)
         ])
 
         if #available(iOS 13.0, *) {
             backButton.setImage(UIImage(systemName: "chevron.left")?.withRenderingMode(.alwaysTemplate), for: .normal)
+            searchButton.setImage(UIImage(systemName: "magnifyingglass")?.withRenderingMode(.alwaysTemplate), for: .normal)
         } else {
             backButton.setTitle("返回", for: .normal)
+            searchButton.setTitle("搜索", for: .normal)
         }
         backButton.accessibilityIdentifier = "epub.reader.back"
+        searchButton.accessibilityIdentifier = "epub.reader.search"
         bookmarkButton.accessibilityIdentifier = "epub.reader.bookmark"
         titleLabel.accessibilityIdentifier = "epub.reader.title"
         updateBookmarkButtonAppearance()
@@ -76,12 +91,14 @@ public final class RDEPUBReaderTopToolView: RDEPUBReaderToolView {
 
     override public func apply(theme: RDEPUBReaderTheme) {
         super.apply(theme: theme)
-        titleLabel.textColor = .black
-        backButton.tintColor = .black
-        bookmarkButton.tintColor = .black
+        titleLabel.textColor = theme.toolControlTextColor
+        backButton.tintColor = theme.toolControlTextColor
+        searchButton.tintColor = theme.toolControlTextColor
+        bookmarkButton.tintColor = theme.toolControlTextColor
         if #unavailable(iOS 13.0) {
-            backButton.setTitleColor(.black, for: .normal)
-            bookmarkButton.setTitleColor(.black, for: .normal)
+            backButton.setTitleColor(theme.toolControlTextColor, for: .normal)
+            searchButton.setTitleColor(theme.toolControlTextColor, for: .normal)
+            bookmarkButton.setTitleColor(theme.toolControlTextColor, for: .normal)
         }
         updateBookmarkButtonAppearance()
     }
@@ -104,6 +121,10 @@ public final class RDEPUBReaderTopToolView: RDEPUBReaderToolView {
         onBack?()
     }
 
+    @objc private func searchAction() {
+        onSearch?()
+    }
+
     @objc private func bookmarkAction() {
         onToggleBookmark?()
     }