Remove all RDEPUBBackgroundTrace.log and bare print diagnostic calls

Keep only the evaluateFullPageMapTakeover: fullReplace diagnostic log
in RDEPUBPageMapReconciliationCoordinator.swift for future debugging.

Simplified RDEPUBBackgroundTrace to just the log method (removed measure
and debug gating). Removed all [EPUB][...], [ReadViewDemo], and
[EPUB][Pagination] print statements across the project.

Also includes earlier bug fixes:
- Fix stale currentPageNumber in extendPartial commit
- Fix pageCurl rebindVisiblePage during transition
- Fix keepCurrentWindow not removing pending update from queue
- Fix right-aligned text (巫鸿 bug) via avoidPageBreakInside,
  tail merger, and continuation paragraph normalization
- Add text-indent reset for aligned blocks in CSS compatibility layer

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

Sources/RDReaderView/EPUBTextRendering/BuildPipeline/RDEPUBTextBookBuilder.swift

@@ -187,16 +187,8 @@ public final class RDEPUBTextBookBuilder {
         let renderDuration = CFAbsoluteTimeGetCurrent() - renderStart
 
         let plainText = rendered.attributedString.string.trimmingCharacters(in: .whitespacesAndNewlines)
-        if item.href.lowercased().contains("cover") {
-            #if DEBUG
-            print("[EPUB][Cover] rendered href=\(item.href) textLength=\(plainText.count) attrLength=\(rendered.attributedString.length) attachments=\(attachmentCount(in: rendered.attributedString))")
-            #endif
-        }
         if shouldSkipChapter(item: item, content: rendered.attributedString, text: plainText) {
             if item.href.lowercased().contains("cover") {
-                #if DEBUG
-                print("[EPUB][Cover] skipped href=\(item.href)")
-                #endif
             }
             return nil
         }
@@ -287,12 +279,6 @@ public final class RDEPUBTextBookBuilder {
             ]
             : normalizedFrames
 
-        if item.href.lowercased().contains("cover") {
-            #if DEBUG
-            print("[EPUB][Cover] paginated href=\(item.href) pages=\(effectiveFrames.count) firstRange=\(effectiveFrames.first.map { NSStringFromRange($0.contentRange) } ?? "none")")
-            #endif
-        }
-
         let chapterAttributedContent = content.copy() as! NSAttributedString
         let pages = effectiveFrames.enumerated().map { localPageIndex, frame in
             let range = frame.contentRange