fix: resolve UI issues (icons, chapter title, AI context)

src/NexusReader.Infrastructure/Services/EpubService.cs

@@ -61,7 +61,13 @@ public class EpubService : IEpubService
             }
 
             var chapterRef = readingOrder[chapterIndex];
-            var chapterTitle = chapterRef.FilePath ?? $"Chapter {chapterIndex + 1}";
+            
+            // Try to find a better title from navigation (TOC)
+            var navigation = bookRef.GetNavigation();
+            var chapterTitle = FindTitleInNavigation(navigation, chapterRef.FilePath) 
+                               ?? Path.GetFileNameWithoutExtension(chapterRef.FilePath) 
+                               ?? $"Chapter {chapterIndex + 1}";
+
             var chapterContent = await chapterRef.ReadContentAsTextAsync();
 
             var blocks = new List<ContentBlock>();
@@ -157,4 +163,25 @@ public class EpubService : IEpubService
             new List<string> { "Podsumuj", "Generuj Quiz", "Pomiń" }
         );
     }
+
+    private string? FindTitleInNavigation(IEnumerable<EpubNavigationItemRef> navigation, string? filePath)
+    {
+        if (string.IsNullOrEmpty(filePath)) return null;
+        
+        var fileName = Path.GetFileName(filePath);
+
+        foreach (var item in navigation)
+        {
+            // Match by full path or just filename as fallback
+            if (item.Link?.ContentFilePath == filePath || item.Link?.ContentFilePath == fileName)
+                return item.Title;
+                
+            if (item.NestedItems != null && item.NestedItems.Any())
+            {
+                var childTitle = FindTitleInNavigation(item.NestedItems, filePath);
+                if (childTitle != null) return childTitle;
+            }
+        }
+        return null;
+    }
 }

src/NexusReader.UI.Shared/Components/Atoms/NexusIcon.razor

@@ -40,6 +40,12 @@
         case "eye-off":
             <path d="M9.88 9.88a3 3 0 1 0 4.24 4.24" /><path d="M10.73 5.08A10.43 10.43 0 0 1 12 5c7 0 10 7 10 7a13.16 13.16 0 0 1-1.67 2.68" /><path d="M6.61 6.61A13.52 13.52 0 0 0 2 12s3 7 10 7a9.74 9.74 0 0 0 5.39-1.61" /><line x1="2" x2="22" y1="2" y2="22" />
             break;
+        case "arrow-left":
+            <path d="M19 12H5M12 19l-7-7 7-7" />
+            break;
+        case "arrow-right":
+            <path d="M5 12h14M12 5l7 7-7 7" />
+            break;
         default:
             <!-- Fallback circle -->
             <circle cx="12" cy="12" r="10" />

src/NexusReader.UI.Shared/Components/Molecules/AiAssistantBubble.razor

@@ -42,6 +42,7 @@
     /// <summary>Fallback static dialogue shown when no live AI content is available.</summary>
     [Parameter] public string Dialogue { get; set; } = string.Empty;
     [Parameter] public List<string> Actions { get; set; } = new();
+    [Parameter] public string FullPageContent { get; set; } = string.Empty;
     [Parameter] public EventCallback<string> OnActionTriggered { get; set; }
 
     private string _displayedText = string.Empty;
@@ -76,8 +77,11 @@
 
         try
         {
-            _packet = await Coordinator.RequestSummaryAndQuizAsync(
-                $"[ID: {ContextBlockId}]\n{Dialogue}");
+            var contentToAnalyze = !string.IsNullOrWhiteSpace(FullPageContent) 
+                ? FullPageContent 
+                : $"[ID: {ContextBlockId}]\n{Dialogue}";
+
+            _packet = await Coordinator.RequestSummaryAndQuizAsync(contentToAnalyze);
 
             var summary = _packet?.Summary;
 

src/NexusReader.UI.Shared/Components/Organisms/ReaderCanvas.razor

@@ -29,6 +29,14 @@
                     {
                         <NexusTypography Variant="NexusTypography.TypographyVariant.Ebook">@((MarkupString)textSegment.Content)</NexusTypography>
                     }
+                    else if (block is AiActionTriggerBlock trigger)
+                    {
+                        <AiAssistantBubble 
+                            ContextBlockId="@trigger.Id" 
+                            Dialogue="@trigger.Dialogue" 
+                            Actions="@trigger.ActionOptions"
+                            FullPageContent="@GetFullPageContent()" />
+                    }
                 </div>
             }
         </div>

src/NexusReader.UI.Shared/Components/Organisms/ReaderFooter.razor

@@ -36,10 +36,9 @@
         NavigationService.OnNavigationChanged += HandleNavigationChanged;
     }
 
-    private Task HandleNavigationChanged()
+    private async Task HandleNavigationChanged()
     {
-        StateHasChanged();
-        return Task.CompletedTask;
+        await InvokeAsync(StateHasChanged);
     }
 
     private int CalculateProgress()

src/NexusReader.UI.Shared/Components/Organisms/ReaderFooter.razor.css

@@ -58,6 +58,7 @@
     justify-content: center;
     min-width: 0;
     overflow: hidden;
+    color: #333;
 }
 
 .chapter-title {