iOS: fix mini player overlap, empty cover square, chapter nav, and UI polish

- Add safeAreaInset on ChapterReaderView ScrollView so Prev/Next buttons
  clear the mini player bar when audio is active
- Fix mini player height reservation (66pt constant via AppLayout)
- Add AsyncCoverImage(isBackground:) to suppress rounded-rect placeholder
  showing through blurred hero background (empty square bug)
- Reduce chapter page size 100→50 on iOS
- Fix ChapterRow date/chevron layout: minLength spacer + fixedSize date
- Add String.strippingTrailingDate() extension; apply in MiniPlayer,
  FullPlayer, and ChapterReader header to clean up stale concatenated titles
- Make Prev/Next buttons equal-width (maxWidth: .infinity) for easier tapping

ios/LibNovel/LibNovel/Views/ChapterReader/ChapterReaderView.swift

@@ -82,7 +82,7 @@ struct ChapterReaderView: View {
             VStack(alignment: .leading, spacing: 16) {
                 // Header
                 VStack(alignment: .leading, spacing: 4) {
-                    Text(content.chapter.title)
+                    Text(content.chapter.title.strippingTrailingDate())
                         .font(.title2.bold())
                     if !content.chapter.dateLabel.isEmpty {
                         Text(content.chapter.dateLabel)
@@ -102,18 +102,19 @@ struct ChapterReaderView: View {
                 Divider()
 
                 // Prev / Next navigation
-                HStack {
+                HStack(spacing: 12) {
                     if let prev = content.prev {
                         NavigationLink(value: NavDestination.chapter(slug, prev)) {
                             Label("Ch.\(prev)", systemImage: "chevron.left")
+                                .frame(maxWidth: .infinity)
                         }
                         .buttonStyle(.bordered)
                     }
-                    Spacer()
                     if let next = content.next {
                         NavigationLink(value: NavDestination.chapter(slug, next)) {
                             Label("Ch.\(next)", systemImage: "chevron.right")
                                 .labelStyle(ReverseLabelStyle())
+                                .frame(maxWidth: .infinity)
                         }
                         .buttonStyle(.borderedProminent)
                         .tint(.amber)
@@ -123,6 +124,12 @@ struct ChapterReaderView: View {
             }
             .padding(.vertical)
         }
+        // Ensure the Prev/Next buttons clear the mini-player bar when it is visible.
+        .safeAreaInset(edge: .bottom) {
+            if audioPlayer.isActive {
+                Color.clear.frame(height: AppLayout.miniPlayerBarHeight)
+            }
+        }
     }
 
     // MARK: - Audio toolbar button