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>

ReadViewDemo/ReadViewDemoUITests/Helpers/AccessibilityIdentifiers.swift

@@ -27,6 +27,14 @@ enum IDs {
     static let readerSelectionText = "epub.reader.selection.text"
     static let readerSelectionHighlight = "epub.reader.selection.高亮"
 
+    static let readerSearch = "epub.reader.search"
+    static let searchBar = "epub.reader.search.bar"
+    static let searchField = "epub.reader.search.field"
+    static let searchPrevious = "epub.reader.search.previous"
+    static let searchNext = "epub.reader.search.next"
+    static let searchClose = "epub.reader.search.close"
+    static let searchCount = "epub.reader.search.count"
+
     static let settingsScroll = "epub.reader.settings.scroll"
     static let settingsBrightness = "epub.reader.settings.brightness"
     static let settingsFontIncrease = "epub.reader.settings.font.increase"

ReadViewDemo/ReadViewDemoUITests/Helpers/XCUIApplication+Launch.swift

@@ -8,7 +8,8 @@ extension XCUIApplication {
         resetsReaderState: Bool = true,
         windowSize: Int? = nil,
         concurrency: Int? = nil,
-        clearsCache: Bool = false
+        clearsCache: Bool = false,
+        searchKeyword: String? = nil
     ) {
         var args = ["--demo-book-title", bookTitleQuery]
         if resetsReaderState {
@@ -29,6 +30,9 @@ extension XCUIApplication {
         if let concurrency {
             args += ["--demo-concurrency", "\(concurrency)"]
         }
+        if let searchKeyword {
+            args += ["--demo-search-keyword", searchKeyword]
+        }
         launchArguments = args
         launch()
     }