feat(ui/arch): Optimize Graph Dynamics, Immersive Reader, and Core Stability (#19)

This PR introduces a major optimization of graph dynamics, immersive reading experience, and architectural stabilization.

### 🚀 Key Improvements

- **Knowledge Graph (Fix #16)**:
  - Implemented smooth D3.js transitions using the General Update Pattern.
  - Added "Neon Flash" entry animations and dynamic node dimming for better focus.
- **Immersive Reader (Fix #12)**:
  - Standardized centered layout (`max-width: 800px`) with **Merriweather** typography.
  - Optimized line-height and letter-spacing for premium readability.
- **Technical Code Blocks (Fix #20)**:
  - High-contrast dark containers for code snippets.
  - **JetBrains Mono** integration and neon-accented scrollbars.
- **Architectural Stabilization**:
  - Enforced a strict **'no async void'** policy in UI services using `Func<Task>`.
  - Resolved WASM runtime DI errors by implementing dummy service proxies for server-side dependencies.
  - Replaced generic 'Not Found' message with a branded Nexus preloader.

Fixes #7, Fixes #12, Fixes #16, Fixes #20.

Reviewed-on: #19
Co-authored-by: Marek Jasiński <jasins.marek@gmail.com>
Co-committed-by: Marek Jasiński <jasins.marek@gmail.com>

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/Molecules/IntelligenceToolbar.razor

@@ -42,7 +42,7 @@
 @code {
     protected override void OnInitialized()
     {
-        FocusMode.OnFocusModeChanged += StateHasChanged;
+        FocusMode.OnFocusModeChanged += HandleUpdate;
     }
 
     private async Task HandleClearCache()
@@ -56,8 +56,10 @@
         }
     }
 
+    private Task HandleUpdate() => InvokeAsync(StateHasChanged);
+
     public void Dispose()
     {
-        FocusMode.OnFocusModeChanged -= StateHasChanged;
+        FocusMode.OnFocusModeChanged -= HandleUpdate;
     }
 }

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

@@ -55,12 +55,14 @@
 
     protected override void OnInitialized()
     {
-        QuizService.OnQuizUpdated += () => InvokeAsync(StateHasChanged);
+        QuizService.OnQuizUpdated += HandleUpdate;
     }
 
+    private Task HandleUpdate() => InvokeAsync(StateHasChanged);
+
     public void Dispose()
     {
-        QuizService.OnQuizUpdated -= StateHasChanged;
+        QuizService.OnQuizUpdated -= HandleUpdate;
     }
 
     private async Task SelectOptionAsync(QuizQuestionDto question, int index)

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

@@ -29,7 +29,7 @@
                     </div>
                     <div class="ai-actions">
                         <button class="action-btn neon-border" @onclick="GenerateFullQuiz">Generuj Quiz dla całej strony</button>
-                        <button class="action-btn ghost" @onclick="Close">Zamknij</button>
+                        <button class="action-btn ghost" @onclick="CloseAsync">Zamknij</button>
                     </div>
                 }
                 else
@@ -39,7 +39,7 @@
                     </div>
                     <div class="ai-actions">
                         <button class="action-btn neon-border" @onclick="RequestSummary">Podsumuj zaznaczenie</button>
-                        <button class="action-btn ghost" @onclick="Close">Pomiń</button>
+                        <button class="action-btn ghost" @onclick="CloseAsync">Pomiń</button>
                     </div>
                 }
             </div>
@@ -76,7 +76,11 @@
     private async Task RequestSummary()
     {
         IsLoading = true;
-        Packet = await Coordinator.RequestSummaryAndQuizAsync(SelectedText);
+        var contextPrompt = !string.IsNullOrWhiteSpace(FullPageContent) 
+            ? $"ANALYSIS CONTEXT (Full Page Content):\n{FullPageContent}\n\nUSER SELECTION TO SUMMARIZE:\n" 
+            : "";
+        
+        Packet = await Coordinator.RequestSummaryAndQuizAsync($"{contextPrompt}{SelectedText}");
         IsLoading = false;
     }
 
@@ -85,12 +89,12 @@
         IsLoading = true;
         await Coordinator.RequestSummaryAndQuizAsync(FullPageContent);
         IsLoading = false;
-        Close();
+        await CloseAsync();
     }
 
-    private void Close()
+    private async Task CloseAsync()
     {
         Packet = null;
-        InteractionService.NotifyTextSelected(string.Empty, string.Empty, null!);
+        await InteractionService.NotifyTextSelected(string.Empty, string.Empty, null!);
     }
 }