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.Application/Queries/User/GetUserProfileQueryHandler.cs

@@ -18,13 +18,15 @@ public class GetUserProfileQueryHandler : IRequestHandler<GetUserProfileQuery, R
     public async Task<Result<UserProfileDto>> Handle(GetUserProfileQuery request, CancellationToken cancellationToken)
     {
         using var dbContext = await _dbContextFactory.CreateDbContextAsync(cancellationToken);
-        var profile = await dbContext.Users
+        
+        var userRaw = await dbContext.Users
             .Where(u => u.Id == request.UserId)
-            .Select(u => new UserProfileDto
+            .Select(u => new
             {
                 Email = u.Email ?? string.Empty,
+                UserId = u.Id,
                 AITokensUsed = u.AITokensUsed,
-                TenantId = u.TenantId != null && u.TenantId.Length == 36 ? new Guid(u.TenantId) : Guid.Empty,
+                TenantIdString = u.TenantId,
                 Plan = u.SubscriptionPlan != null ? new SubscriptionPlanDto
                 {
                     Id = u.SubscriptionPlan.Id,
@@ -32,9 +34,17 @@ public class GetUserProfileQueryHandler : IRequestHandler<GetUserProfileQuery, R
                     AITokenLimit = u.SubscriptionPlan.AITokenLimit,
                     MonthlyPrice = u.SubscriptionPlan.MonthlyPrice
                 } : new SubscriptionPlanDto(),
-                AverageQuizScore = u.QuizResults.Any(q => q.TotalQuestions > 0) 
-                    ? (int)u.QuizResults.Where(q => q.TotalQuestions > 0).Average(q => (double)q.Score / q.TotalQuestions * 100) 
-                    : 0,
+                QuizResults = u.QuizResults.Select(q => new
+                {
+                    q.Score,
+                    q.TotalQuestions,
+                    q.Id,
+                    q.Topic,
+                    q.Percentage,
+                    q.CompletedDate
+                }).ToList(),
+                DisplayName = u.DisplayName,
+                BooksReadCount = u.Ebooks.Count(),
                 LastReadBook = u.Ebooks.OrderByDescending(e => e.LastReadDate).Select(e => new LastReadBookDto
                 {
                     Id = e.Id,
@@ -48,7 +58,8 @@ public class GetUserProfileQueryHandler : IRequestHandler<GetUserProfileQuery, R
                     Progress = e.Progress,
                     LastChapter = e.LastChapter ?? "Rozpoczynanie...",
                     LastChapterIndex = e.LastChapterIndex,
-                    Description = e.Description
+                    Description = e.Description,
+                    IsReadyForReading = e.IsReadyForReading
                 }).FirstOrDefault(),
                 Roles = dbContext.UserRoles
                     .Where(ur => ur.UserId == u.Id)
@@ -57,11 +68,59 @@ public class GetUserProfileQueryHandler : IRequestHandler<GetUserProfileQuery, R
             })
             .FirstOrDefaultAsync(cancellationToken);
 
-        if (profile == null)
+        if (userRaw == null)
         {
             return Result.Fail("Profile not found.");
         }
 
+        var tenantId = userRaw.TenantIdString;
+        var mappedConcepts = await dbContext.KnowledgeUnits
+            .Where(k => k.TenantId == tenantId || k.TenantId == "global" || string.IsNullOrEmpty(k.TenantId))
+            .OrderByDescending(k => k.CreatedAt)
+            .Take(6)
+            .Select(k => new MappedConceptDto
+            {
+                Id = k.Id,
+                Type = k.Type.ToString(),
+                Content = k.Content
+            })
+            .ToListAsync(cancellationToken);
+
+        var conceptsMappedCount = await dbContext.KnowledgeUnits
+            .CountAsync(k => k.TenantId == tenantId || k.TenantId == "global" || string.IsNullOrEmpty(k.TenantId), cancellationToken);
+
+        int averageQuizScore = 0;
+        var validQuizzes = userRaw.QuizResults.Where(q => q.TotalQuestions > 0).ToList();
+        if (validQuizzes.Count > 0)
+        {
+            averageQuizScore = (int)(validQuizzes.Average(q => (double)q.Score / q.TotalQuestions) * 100);
+        }
+
+        var profile = new UserProfileDto
+        {
+            Email = userRaw.Email,
+            UserId = userRaw.UserId,
+            AITokensUsed = userRaw.AITokensUsed,
+            TenantId = userRaw.TenantIdString != null && userRaw.TenantIdString.Length == 36 ? new Guid(userRaw.TenantIdString) : Guid.Empty,
+            Plan = userRaw.Plan,
+            AverageQuizScore = averageQuizScore,
+            DisplayName = userRaw.DisplayName,
+            BooksReadCount = userRaw.BooksReadCount,
+            ConceptsMappedCount = conceptsMappedCount,
+            LastReadBook = userRaw.LastReadBook,
+            RecentQuizzes = userRaw.QuizResults.OrderByDescending(q => q.CompletedDate).Take(5).Select(q => new QuizResultDto
+            {
+                Id = q.Id,
+                Topic = q.Topic,
+                Score = q.Score,
+                TotalQuestions = q.TotalQuestions,
+                Percentage = q.Percentage,
+                CompletedDate = q.CompletedDate
+            }).ToList(),
+            MappedConcepts = mappedConcepts,
+            Roles = userRaw.Roles
+        };
+
         return Result.Ok(profile);
     }
 }