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/EPUBUI/ReaderController/RDEPUBMetadataParseCancellationController.swift

@@ -0,0 +1,44 @@
+import Foundation
+
+final class RDEPUBMetadataParseCancellationController {
+
+    let token: UUID
+
+    private let lock = NSLock()
+
+    private weak var queue: OperationQueue?
+
+    private var cancelled = false
+
+    init(token: UUID) {
+        self.token = token
+    }
+
+    func attach(queue: OperationQueue) {
+        let shouldCancelImmediately: Bool
+        lock.lock()
+        self.queue = queue
+        shouldCancelImmediately = cancelled
+        lock.unlock()
+
+        if shouldCancelImmediately {
+            queue.cancelAllOperations()
+        }
+    }
+
+    func cancel() {
+        let queueToCancel: OperationQueue?
+        lock.lock()
+        cancelled = true
+        queueToCancel = queue
+        lock.unlock()
+        queueToCancel?.cancelAllOperations()
+    }
+
+    var isCancelled: Bool {
+        lock.lock()
+        let value = cancelled
+        lock.unlock()
+        return value
+    }
+}