feat(search/rag): implement NexusSearchBox, dynamic Qdrant collection auto-provisioning, batch vector ingestion, mobile Serilog logging, and resolve 401 auth handler error (#51)

Resolves #52

This Pull Request introduces the **NexusSearchBox** search feature with premium unified styling, implements a robust **dynamic Qdrant collection auto-provisioning and batch-vector ingestion pipeline**, integrates a unified **Serilog logging infrastructure** for the Blazor Hybrid environment (MAUI), and resolves the **401 Unauthorized API header propagation error** inside mobile builds.

### 🚀 Key Implementations

#### 1. Premium `NexusSearchBox` & Semantic Search UI
* **NexusSearchBox Component:** Created an elegant search-as-you-type search box with smooth key navigation, quick-clearing, and seamless dynamic styling.
* **Unified Aesthetics:** Refactored the search box isolated styling to align perfectly with the dashboard's design system using glassmorphism, `--nexus-neon` token gradients, and smooth pulse/fade animations.
* **Semantic Search Integration:** Integrated semantic search query dispatching (`SearchLibrarySemanticallyQuery`) and wired up navigation seamlessly through the updated `ReaderNavigationService`.
* **Tests Hardening:** Added/adapted query assertions in `QueryTests.cs` to guarantee safe parameterization and error boundary mapping.

#### 2. Qdrant Collection Provisioning & Vector Ingestion
* **Dynamic Auto-Provisioning:** Implemented dynamic checking and lazy-creation of the `knowledge_units` collection using 768 dimensions and Cosine distance.
* **High-Performance Ingestion:** Optimized `ProcessKnowledgeUnitsAsync` with high-performance batch embedding generation using `_embeddingGenerator` and deterministic MD5 GUIDs for stable, duplicate-free upsertion.
* **Database Cache Clear Sync:** Integrated Qdrant collection deletion in `ClearCacheAsync` to ensure absolute consistency between the PostgreSQL database cache and vector database indices.

#### 3. Cross-Platform MAUI Logging (Serilog Infrastructure)
* **Serilog Integration:** Configured cross-platform Serilog routing in `SerilogConfiguration.cs`, streaming diagnostic logs safely across native platforms and the Blazor Webview container.
* **Interop Bridge:** Built `BlazorLoggingBridge.cs` to capture web console messages and pipe them directly to the native host logger.
* **Demo Interface:** Added an interactive `SerilogDemo.razor` sandbox under Pages.

#### 4. Resolving 401 Load Errors (Authentication Handler Flow)
* **Authentication Header Handler:** Implemented the `MobileAuthenticationHeaderHandler` to correctly extract, validate, and inject bearer JWT tokens into outbound API requests.
* **Configuration-based API Host:** Structured standard API URI routing to use clean configuration bindings in `appsettings.json`.

---

### 🧪 Verification & Build Status
* Run `dotnet build` from the solution root: Successfully compiled the full multi-targeted solution (`Liczba błędów: 0`).
* All unit and integration tests successfully executed and verified (`dotnet test`).

---------

Co-authored-by: Marek Jasiński <jasins.marek@gmail.com>
Co-authored-by: Marek Jaisński <jasins.marek@gmail.com>
Reviewed-on: #51
Co-authored-by: Antigravity <antigravity@google.com>
Co-committed-by: Antigravity <antigravity@google.com>

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

@@ -2,9 +2,14 @@
 @using NexusReader.Application.Queries.Quiz
 @using NexusReader.Application.Commands.Quiz
 @using NexusReader.Application.Abstractions.Services
+@using NexusReader.UI.Shared.Components.Atoms
+@using NexusReader.UI.Shared.Services
 @inject IMediator Mediator
 @inject IPlatformService PlatformService
 @inject IQuizStateService QuizService
+@inject IIdentityService IdentityService
+@inject IKnowledgeGraphService GraphService
+@inject KnowledgeCoordinator Coordinator
 
 <div class="knowledge-check">
     <div class="quiz-header">
@@ -12,10 +17,33 @@
         <button class="expand-btn">⌵</button>
     </div>
 
-    @if (QuizService.IsHydrating)
+    @if (QuizService.IsHydrating || _isGenerating)
     {
         <div class="loading-state shimmer">Skanowanie wiedzy przez AI...</div>
     }
+    else if (_isSubmitted)
+    {
+        <div class="submitted-container">
+            <div class="success-icon-wrapper">
+                <NexusIcon Name="check" Size="48" Class="success-glow" />
+            </div>
+            <h3 class="submitted-title">Gratulacje!</h3>
+            <p class="submitted-text">Sprawdzian zakończony pomyślnie. Twój wynik został zapisany w bazie danych.</p>
+            
+            <div class="score-card">
+                <div class="score-main">
+                    <span class="score-num">@_score</span>
+                    <span class="score-divider">/</span>
+                    <span class="score-total">@_totalQuestions</span>
+                </div>
+                <div class="score-percent">@((int)_percentage)% poprawnych odpowiedzi</div>
+            </div>
+
+            <button class="reset-quiz-btn" @onclick="CloseQuiz">
+                <span>ZAKOŃCZ</span>
+            </button>
+        </div>
+    }
     else if (QuizService.CurrentQuiz != null)
     {
         <div class="quiz-body">
@@ -41,17 +69,45 @@
             }
             
             <div class="quiz-footer">
-                <button class="submit-btn" disabled="@(!AllQuestionsAnswered())">Wyślij</button>
+                <button class="submit-btn" disabled="@(!AllQuestionsAnswered() || _isSubmitting)" @onclick="SubmitQuizAsync">
+                    @if (_isSubmitting)
+                    {
+                        <span>Zapisywanie...</span>
+                    }
+                    else
+                    {
+                        <span>Wyślij</span>
+                    }
+                </button>
             </div>
         </div>
     }
+    else
+    {
+        <div class="empty-quiz-state">
+            <div class="empty-icon-wrapper">
+                <NexusIcon Name="robot" Size="48" Class="neon-glow" />
+            </div>
+            <h3 class="empty-title">Brak Aktywnego Quizu</h3>
+            <p class="empty-text">Generuj spersonalizowany sprawdzian wiedzy na podstawie bieżącego rozdziału książki.</p>
+            
+            <button class="generate-quiz-btn" @onclick="GenerateChapterQuizAsync" disabled="@(string.IsNullOrWhiteSpace(Coordinator.CurrentFullPageContent))">
+                <span>GENERUJ QUIZ DLA ROZDZIAŁU</span>
+            </button>
+        </div>
+    }
 </div>
 
-
 @code {
     [Parameter] public string ContextBlockId { get; set; } = string.Empty;
 
     private Dictionary<QuizQuestionDto, (int SelectedIndex, bool IsCorrect)> _states = new();
+    private bool _isSubmitting = false;
+    private bool _isSubmitted = false;
+    private bool _isGenerating = false;
+    private int _score = 0;
+    private int _totalQuestions = 0;
+    private double _percentage = 0.0;
 
     protected override void OnInitialized()
     {
@@ -65,6 +121,24 @@
         QuizService.OnQuizUpdated -= HandleUpdate;
     }
 
+    private async Task GenerateChapterQuizAsync()
+    {
+        if (_isGenerating || string.IsNullOrWhiteSpace(Coordinator.CurrentFullPageContent)) return;
+
+        _isGenerating = true;
+        StateHasChanged();
+
+        try
+        {
+            await Coordinator.RequestSummaryAndQuizAsync(Coordinator.CurrentFullPageContent);
+        }
+        finally
+        {
+            _isGenerating = false;
+            StateHasChanged();
+        }
+    }
+
     private async Task SelectOptionAsync(QuizQuestionDto question, int index)
     {
         if (_states.ContainsKey(question)) return;
@@ -90,6 +164,67 @@
         return QuizService.CurrentQuiz != null && _states.Count == QuizService.CurrentQuiz.Questions.Count;
     }
 
+    private async Task SubmitQuizAsync()
+    {
+        if (QuizService.CurrentQuiz == null || !AllQuestionsAnswered() || _isSubmitting) return;
+
+        _isSubmitting = true;
+        StateHasChanged();
+
+        try
+        {
+            _score = _states.Values.Count(s => s.IsCorrect);
+            _totalQuestions = QuizService.CurrentQuiz.Questions.Count;
+            _percentage = _totalQuestions > 0 ? ((double)_score / _totalQuestions) * 100 : 0.0;
+
+            string topic = "Quiz wiedzy";
+            var graph = GraphService.CurrentGraphData;
+            if (graph != null && !string.IsNullOrEmpty(QuizService.CurrentQuizBlockId))
+            {
+                var node = graph.Nodes.FirstOrDefault(n => n.Id == QuizService.CurrentQuizBlockId);
+                if (node != null && !string.IsNullOrEmpty(node.Label))
+                {
+                    topic = $"Test: {node.Label}";
+                }
+            }
+
+            var profileResult = await IdentityService.GetProfileAsync();
+            if (profileResult.IsSuccess && profileResult.Value != null)
+            {
+                var userId = profileResult.Value.UserId;
+
+                var cmd = new SubmitQuizResultCommand(userId, topic, _score, _totalQuestions);
+                var result = await Mediator.Send(cmd);
+                
+                if (result.IsSuccess)
+                {
+                    IdentityService.ClearCache();
+                    _isSubmitted = true;
+                    await PlatformService.VibrateSuccessAsync();
+                }
+                else
+                {
+                    await PlatformService.VibrateErrorAsync();
+                }
+            }
+        }
+        catch
+        {
+            await PlatformService.VibrateErrorAsync();
+        }
+        finally
+        {
+            _isSubmitting = false;
+            StateHasChanged();
+        }
+    }
+
+    private void CloseQuiz()
+    {
+        _isSubmitted = false;
+        _states.Clear();
+        QuizService.SetQuiz(null, null);
+    }
 
     private string GetBlockClass(QuizQuestionDto question)
     {