feat: EPUB阅读器搜索、注释、CFI模块及大书远距跳转优化

- 实现EPUB阅读器搜索功能及选中注释功能
- 优化CFI模块，修复代码审查发现的11个问题
- 实现大书远距目录跳转与后台补全优化方案
- 优化设置面板与章节运行时联动
- 重构及大量改进优化

Sources/RDReaderView/EPUBUI/ReaderController/RDEPUBBackgroundCoverageStore.swift

@@ -1,65 +1,56 @@
 import Foundation
 
-/// 后台覆盖段：表示某一段章节范围的稳定页码覆盖
 struct RDEPUBBackgroundCoverageSegment {
-    /// 段的下界 spineIndex
+
     let lowerSpineIndex: Int
-    /// 段的上界 spineIndex
+
     let upperSpineIndex: Int
-    /// 页图数据
+
     let pageMap: RDEPUBBookPageMap
-    /// 已解析的 spineIndex 集合
+
     let resolvedSpineIndices: Set<Int>
-    /// 创建时间
+
     let generatedAt: CFAbsoluteTime
-    /// 渲染签名
+
     let renderSignature: String
-    /// 预估内存占用（字节）
+
     let estimatedMemoryBytes: Int
 
-    /// 是否包含指定 spineIndex
     func contains(spineIndex: Int) -> Bool {
         spineIndex >= lowerSpineIndex && spineIndex <= upperSpineIndex
     }
 
-    /// 与指定 spineIndex 的距离
     func distance(to spineIndex: Int) -> Int {
         if contains(spineIndex: spineIndex) { return 0 }
         return min(abs(spineIndex - lowerSpineIndex), abs(spineIndex - upperSpineIndex))
     }
 }
 
-/// 覆盖存储策略
 struct RDEPUBBackgroundCoverageStorePolicy {
-    /// 最大常驻段数
+
     let maxResidentSegments: Int
-    /// 单段最大章节数
+
     let maxChaptersPerSegment: Int
-    /// 内存预算（字节）
+
     let memoryBudgetBytes: Int
 
-    /// 默认策略
     static let `default` = RDEPUBBackgroundCoverageStorePolicy(
         maxResidentSegments: 8,
         maxChaptersPerSegment: 256,
-        memoryBudgetBytes: 8 * 1024 * 1024 // 8MB
+        memoryBudgetBytes: 8 * 1024 * 1024 
     )
 }
 
-/// 后台覆盖存储管理器
 final class RDEPUBBackgroundCoverageStore {
+
     private unowned let context: RDEPUBReaderContext
 
-    /// 存储策略
     private let policy: RDEPUBBackgroundCoverageStorePolicy
 
-    /// 存储的段列表
     private var segments: [RDEPUBBackgroundCoverageSegment] = []
 
-    /// 当前总内存占用
     private var currentMemoryBytes: Int = 0
 
-    /// 最后访问时间（用于 LRU 淘汰）
     private var lastAccessTime: [Int: CFAbsoluteTime] = [:]
 
     init(context: RDEPUBReaderContext, policy: RDEPUBBackgroundCoverageStorePolicy = .default) {
@@ -67,12 +58,10 @@ final class RDEPUBBackgroundCoverageStore {
         self.policy = policy
     }
 
-    /// 添加段
     func addSegment(_ segment: RDEPUBBackgroundCoverageSegment) {
-        // 检查是否需要淘汰
+
         evictIfNeeded(forNewSegment: segment)
 
-        // 检查是否与现有段重叠，合并或替换
         var merged = false
         for (index, existing) in segments.enumerated() {
             if canMerge(existing, segment) {
@@ -94,7 +83,6 @@ final class RDEPUBBackgroundCoverageStore {
             currentMemoryBytes += segment.estimatedMemoryBytes
         }
 
-        // 更新访问时间
         lastAccessTime[segment.lowerSpineIndex] = CFAbsoluteTimeGetCurrent()
 
         RDEPUBBackgroundTrace.log(
@@ -103,7 +91,6 @@ final class RDEPUBBackgroundCoverageStore {
         )
     }
 
-    /// 查找覆盖指定 spineIndex 的段
     func findSegment(containing spineIndex: Int) -> RDEPUBBackgroundCoverageSegment? {
         let segment = segments.first { $0.contains(spineIndex: spineIndex) }
         if let segment {
@@ -112,7 +99,6 @@ final class RDEPUBBackgroundCoverageStore {
         return segment
     }
 
-    /// 查找覆盖指定 spineIndex 集合的段
     func findSegment(covering spineIndices: Set<Int>) -> RDEPUBBackgroundCoverageSegment? {
         let segment = segments.first { segment in
             spineIndices.allSatisfy { segment.contains(spineIndex: $0) }
@@ -123,19 +109,16 @@ final class RDEPUBBackgroundCoverageStore {
         return segment
     }
 
-    /// 获取所有段
     func allSegments() -> [RDEPUBBackgroundCoverageSegment] {
         segments
     }
 
-    /// 清除所有段
     func clearAll() {
         segments.removeAll()
         currentMemoryBytes = 0
         lastAccessTime.removeAll()
     }
 
-    /// 清除冷区段（不覆盖当前阅读位置和保护区的段）
     func clearColdSegments(
         activeWindowSpineIndices: Set<Int>,
         protectedSpineIndices: Set<Int>
@@ -151,7 +134,6 @@ final class RDEPUBBackgroundCoverageStore {
         }
     }
 
-    /// 处理内存警告
     func handleMemoryWarning(
         activeWindowSpineIndices: Set<Int>,
         protectedSpineIndices: Set<Int>
@@ -161,15 +143,13 @@ final class RDEPUBBackgroundCoverageStore {
             "memory warning: clearing cold segments, current=\(currentMemoryBytes)B"
         )
 
-        // 第一步：清除冷区段
         clearColdSegments(
             activeWindowSpineIndices: activeWindowSpineIndices,
             protectedSpineIndices: protectedSpineIndices
         )
 
-        // 如果仍然超限，清除更多段
         if currentMemoryBytes > policy.memoryBudgetBytes {
-            // 按距离排序，清除最远的段
+
             let sorted = segments.sorted { lhs, rhs in
                 let lhsDistance = lhs.resolvedSpineIndices.map { idx in
                     activeWindowSpineIndices.map { abs(idx - $0) }.min() ?? Int.max
@@ -194,24 +174,20 @@ final class RDEPUBBackgroundCoverageStore {
         )
     }
 
-    /// 检查是否需要淘汰
     private func evictIfNeeded(forNewSegment newSegment: RDEPUBBackgroundCoverageSegment) {
-        // 检查段数限制
+
         while segments.count >= policy.maxResidentSegments {
             evictLeastRecentlyUsed()
         }
 
-        // 检查内存限制
         while currentMemoryBytes + newSegment.estimatedMemoryBytes > policy.memoryBudgetBytes {
             evictLeastRecentlyUsed()
         }
     }
 
-    /// 淘汰最近最少使用的段
     private func evictLeastRecentlyUsed() {
         guard !segments.isEmpty else { return }
 
-        // 找到最久未访问的段
         var oldestTime = CFAbsoluteTimeGetCurrent()
         var oldestIndex = 0
         for (index, segment) in segments.enumerated() {
@@ -232,33 +208,27 @@ final class RDEPUBBackgroundCoverageStore {
         )
     }
 
-    /// 检查两个段是否可以合并
     private func canMerge(_ lhs: RDEPUBBackgroundCoverageSegment, _ rhs: RDEPUBBackgroundCoverageSegment) -> Bool {
-        // 渲染签名必须相同
+
         guard lhs.renderSignature == rhs.renderSignature else { return false }
 
-        // 检查是否重叠或相邻
         let overlap = lhs.upperSpineIndex >= rhs.lowerSpineIndex - 1 &&
                      rhs.upperSpineIndex >= lhs.lowerSpineIndex - 1
         return overlap
     }
 
-    /// 合并两个段
     private func mergeSegments(_ lhs: RDEPUBBackgroundCoverageSegment, _ rhs: RDEPUBBackgroundCoverageSegment) -> RDEPUBBackgroundCoverageSegment? {
         let newLower = min(lhs.lowerSpineIndex, rhs.lowerSpineIndex)
         let newUpper = max(lhs.upperSpineIndex, rhs.upperSpineIndex)
         let newChapterCount = newUpper - newLower + 1
 
-        // 检查合并后是否超过单段最大章节数
         if newChapterCount > policy.maxChaptersPerSegment {
-            // 按当前阅读位置切分
+
             return nil
         }
 
-        // 合并 resolvedSpineIndices
         let newResolved = lhs.resolvedSpineIndices.union(rhs.resolvedSpineIndices)
 
-        // 合并页图
         let newerSegment = lhs.generatedAt <= rhs.generatedAt ? rhs : lhs
         let olderSegment = lhs.generatedAt <= rhs.generatedAt ? lhs : rhs
         let newPageMap = mergePageMaps(olderSegment.pageMap, newerSegment.pageMap)
@@ -274,7 +244,6 @@ final class RDEPUBBackgroundCoverageStore {
         )
     }
 
-    /// 合并两个页图
     private func mergePageMaps(_ older: RDEPUBBookPageMap, _ newer: RDEPUBBookPageMap) -> RDEPUBBookPageMap {
         var builder = RDEPUBBookPageMap.Builder()
         var entriesBySpineIndex: [Int: RDEPUBBookPageMapEntry] = [:]
@@ -300,7 +269,6 @@ final class RDEPUBBackgroundCoverageStore {
         return builder.build()
     }
 
-    /// 估算内存占用
     private func estimateMemoryBytes(pageMap: RDEPUBBookPageMap, resolvedCount: Int) -> Int {
         256 + pageMap.entries.count * 96 + resolvedCount * 16
     }