refactor: rename RDReaderView -> RDEpubReaderView, update pod config and docs

- Rename source module from RDReaderView to RDEpubReaderView
- Move all source files from Sources/RDReaderView/ to Sources/RDEpubReaderView/
- Update podspec: RDReaderView.podspec -> RDEpubReaderView.podspec
- Update Podfile, demo project, and CocoaPods config for new pod name
- Delete old RDReaderView pod support files from ReadViewDemo/Pods
- Add new RDEpubReaderView pod support files
- Update documentation (API ref, architecture, UML, conventions, etc.)
- Add FixedLayoutRotationTests
- Update .gitignore: exclude .DS_Store, manual unpack backups, _ssoft-output

Sources/RDEpubReaderView/EPUBUI/RDEPUBReaderDelegate.swift

@@ -0,0 +1,56 @@
+import UIKit
+
+public protocol RDEPUBReaderDelegate: AnyObject {
+
+    func epubReader(_ reader: UIViewController, didOpen publication: RDEPUBPublication)
+
+    func epubReader(_ reader: UIViewController, didUpdateLocation location: RDEPUBLocation)
+
+    func epubReaderDidReachEnd(_ reader: UIViewController)
+
+    func epubReader(_ reader: UIViewController, didChangeSelection selection: RDEPUBSelection?)
+
+    func epubReader(_ reader: UIViewController, didUpdateHighlights highlights: [RDEPUBHighlight])
+
+    func epubReader(_ reader: UIViewController, didUpdateBookmarks bookmarks: [RDEPUBBookmark])
+
+    func epubReader(_ reader: UIViewController, didUpdateSearchResult result: RDEPUBSearchResult?)
+
+    func epubReader(_ reader: UIViewController, didChangeCurrentSearchMatch match: RDEPUBSearchMatch?)
+
+    func epubReader(_ reader: UIViewController, didUpdateCurrentTableOfContentsItem item: RDEPUBReaderTableOfContentsItem?)
+
+    func epubReader(_ reader: UIViewController, didActivateExternalLink url: URL)
+
+    func epubReader(_ reader: UIViewController, shouldOpenExternalURL url: URL) -> Bool
+
+    func epubReader(_ reader: UIViewController, didFailWithError error: Error)
+
+    func epubReader(_ reader: UIViewController, configureTopToolView topToolView: RDEPUBReaderTopToolViewProviding)
+
+    /// 提供试读墙视图（configuration.trialPolicy 非 nil 时生效）。
+    /// 返回非 nil 时，阅读器在最后一个可读页之后追加一页展示该视图；返回 nil 则不追加试读墙。
+    /// 视图的购买 / 登录按钮由宿主自行处理（可在点击后调用 reloadBook() 切换到完整 epub）。
+    func epubReaderTrialWallView(_ reader: UIViewController) -> UIView?
+
+    /// 用户翻到试读墙页时回调（宿主可在此触发购买引导 / 埋点等）。
+    func epubReaderDidReachTrialWall(_ reader: UIViewController)
+}
+
+public extension RDEPUBReaderDelegate {
+    func epubReader(_ reader: UIViewController, didOpen publication: RDEPUBPublication) {}
+    func epubReader(_ reader: UIViewController, didUpdateLocation location: RDEPUBLocation) {}
+    func epubReaderDidReachEnd(_ reader: UIViewController) {}
+    func epubReader(_ reader: UIViewController, didChangeSelection selection: RDEPUBSelection?) {}
+    func epubReader(_ reader: UIViewController, didUpdateHighlights highlights: [RDEPUBHighlight]) {}
+    func epubReader(_ reader: UIViewController, didUpdateBookmarks bookmarks: [RDEPUBBookmark]) {}
+    func epubReader(_ reader: UIViewController, didUpdateSearchResult result: RDEPUBSearchResult?) {}
+    func epubReader(_ reader: UIViewController, didChangeCurrentSearchMatch match: RDEPUBSearchMatch?) {}
+    func epubReader(_ reader: UIViewController, didUpdateCurrentTableOfContentsItem item: RDEPUBReaderTableOfContentsItem?) {}
+    func epubReader(_ reader: UIViewController, didActivateExternalLink url: URL) {}
+    func epubReader(_ reader: UIViewController, shouldOpenExternalURL url: URL) -> Bool { true }
+    func epubReader(_ reader: UIViewController, didFailWithError error: Error) {}
+    func epubReader(_ reader: UIViewController, configureTopToolView topToolView: RDEPUBReaderTopToolViewProviding) {}
+    func epubReaderTrialWallView(_ reader: UIViewController) -> UIView? { nil }
+    func epubReaderDidReachTrialWall(_ reader: UIViewController) {}
+}