feat: 交互协调器拆分、附件提示、暗色图片适配、选区放大镜及文档清理

- 拆分 ContentDelegates/TextContentView 为独立协调器（InteractionCoordinator、LocationResolution、ExternalLinks、AttachmentTooltip）
- 新增 RDEPUBAttachmentTooltipView/OverlayView 附件气泡提示
- 新增 RDEPUBDarkImageAdjuster 暗色模式图片亮度适配
- 新增 RDEPUBSelectionLoupeView 选区放大镜
- 新增 MetadataParseWorker/CancellationController 元数据解析取消机制
- 重构 PresentationRuntime/PaginationCoordinator 精简职责
- 优化 ChapterLoader/WarmupOrchestrator 异步章节加载
- CFI 模块微调与 NoteModels 更新
- 清理冗余文档，更新架构/UML/业务逻辑文档

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

Sources/RDReaderView/EPUBCore/CFI/RDEPUBCFIDOMPathBuilder.swift

@@ -75,7 +75,7 @@ public enum RDEPUBCFIDOMPathBuilder {
               match.numberOfRanges > 2 else {
             return nil
         }
-        return nsAttributes.substring(with: match.range(at: 2)).rd_cfiNilIfEmpty
+        return nsAttributes.substring(with: match.range(at: 2)).rd_nilIfEmpty
     }
 
     static func isIgnorableTag(_ tagName: String) -> Bool {
@@ -138,8 +138,8 @@ enum RDEPUBCFITextNodeMapBuilder {
             markers: markers,
             pathRanges: pathRanges,
             recoveryMetadata: RDEPUBCFIRecoveryMetadata(
-                domFingerprint: rawHTML.sha256Hex,
-                normalizedTextChecksum: normalizedChapter.normalizedText.sha256Hex,
+                domFingerprint: rawHTML.rd_sha256Hex,
+                normalizedTextChecksum: normalizedChapter.normalizedText.rd_sha256Hex,
                 tokenIndex: makeTokenAnchors(
                     normalizedChapter: normalizedChapter,
                     markers: markers,
@@ -516,14 +516,6 @@ private struct RDEPUBNormalizedTextIndex {
     }
 }
 
-extension String {
-    var rd_cfiNilIfEmpty: String? {
-        let trimmed = trimmingCharacters(in: .whitespacesAndNewlines)
-        return trimmed.isEmpty ? nil : trimmed
-    }
-
-}
-
 private extension String {
     var fnv1a64: UInt64 {
         let offsetBasis: UInt64 = 14695981039346656037