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/Services/KnowledgeCoordinator.cs

@@ -36,10 +36,10 @@ public sealed partial class KnowledgeCoordinator : IDisposable
         _interactionService.OnNodeSelected += HandleNodeSelected;
     }
 
-    private void HandleNodeSelected(string nodeId)
+    private async Task HandleNodeSelected(string nodeId)
     {
-        _interactionService.RequestScrollToBlock(nodeId);
-        _interactionService.RequestHighlightBlock(nodeId);
+        await _interactionService.RequestScrollToBlock(nodeId);
+        await _interactionService.RequestHighlightBlock(nodeId);
     }
 
     public async Task ProcessFullPageAsync(string fullContent, string tenantId = "global")
@@ -48,8 +48,8 @@ public sealed partial class KnowledgeCoordinator : IDisposable
 
         LogGeneratingGraph(tenantId);
         
-        _graphService.Clear();
-        _graphService.SetLoading(true);
+        await _graphService.Clear();
+        await _graphService.SetLoading(true);
         
         try
         {
@@ -59,7 +59,7 @@ public sealed partial class KnowledgeCoordinator : IDisposable
                 var packet = result.Value;
                 if (packet.Graph != null)
                 {
-                    _graphService.UpdateGraph(packet.Graph);
+                    await _graphService.UpdateGraph(packet.Graph);
                     OnGraphUpdated?.Invoke(packet.Graph);
                     await _platformService.VibrateSuccessAsync();
                 }
@@ -71,10 +71,10 @@ public sealed partial class KnowledgeCoordinator : IDisposable
         }
     }
 
-    public void OnBlockReached(string blockId, string content)
+    public async Task OnBlockReachedAsync(string blockId, string content)
     {
         // Only update active node for "TU JESTEŚ" logic, do NOT trigger highlight here
-        _graphService.SetActiveNode(blockId);
+        await _graphService.SetActiveNode(blockId);
     }
 
     public async Task<KnowledgePacket?> RequestSummaryAndQuizAsync(string content, string tenantId = "global")
@@ -109,9 +109,9 @@ public sealed partial class KnowledgeCoordinator : IDisposable
         return null;
     }
 
-    public void Clear()
+    public async Task ClearAsync()
     {
-        _graphService.Clear();
+        await _graphService.Clear();
         _quizService.SetQuiz(null, null);
     }