refactor: introduce IConceptsMapReadRepository and SegmentIdParser to improve data access and domain logic encapsulation.

src/NexusReader.Application/Abstractions/Persistence/IConceptsMapReadRepository.cs

@@ -0,0 +1,23 @@
+using NexusReader.Domain.Entities;
+
+namespace NexusReader.Application.Abstractions.Persistence;
+
+/// <summary>
+/// Read-only abstraction for fetching concepts map data.
+/// Defined in the Application layer to avoid a direct dependency on EF Core / NexusReader.Data.
+/// </summary>
+public interface IConceptsMapReadRepository
+{
+    /// <summary>
+    /// Gets the last read page ID for the specified user.
+    /// </summary>
+    Task<string?> GetLastReadPageIdAsync(string userId, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Gets all knowledge units associated with a book, scoped by tenant.
+    /// </summary>
+    Task<List<KnowledgeUnit>> GetKnowledgeUnitsForBookAsync(
+        Guid bookId,
+        string tenantId,
+        CancellationToken cancellationToken = default);
+}

src/NexusReader.Application/Queries/Concepts/GetBookConceptsMapQueryHandler.cs

@@ -5,45 +5,30 @@ using System.Text.Json;
 using System.Threading;
 using System.Threading.Tasks;
 using FluentResults;
-using Microsoft.EntityFrameworkCore;
 using NexusReader.Application.Abstractions.Messaging;
+using NexusReader.Application.Abstractions.Persistence;
 using NexusReader.Application.Queries.Graph;
-using NexusReader.Data.Persistence;
+using NexusReader.Application.Utilities;
 
 namespace NexusReader.Application.Queries.Concepts;
 
 internal sealed class GetBookConceptsMapQueryHandler : IQueryHandler<GetBookConceptsMapQuery, BookConceptsMapResultDto>
 {
-    private readonly IDbContextFactory<AppDbContext> _dbContextFactory;
+    private readonly IConceptsMapReadRepository _repository;
 
-    public GetBookConceptsMapQueryHandler(IDbContextFactory<AppDbContext> dbContextFactory)
+    public GetBookConceptsMapQueryHandler(IConceptsMapReadRepository repository)
     {
-        _dbContextFactory = dbContextFactory;
+        _repository = repository;
     }
 
     public async Task<Result<BookConceptsMapResultDto>> Handle(GetBookConceptsMapQuery request, CancellationToken cancellationToken)
     {
-        using var dbContext = await _dbContextFactory.CreateDbContextAsync(cancellationToken);
-
         // 1. Fetch user to extract reading progress (LastReadPageId)
-        var user = await dbContext.Users
+        var lastReadPageId = await _repository.GetLastReadPageIdAsync(request.UserId, cancellationToken);
-            .Where(u => u.Id == request.UserId)
+        var lastReadBlockId = lastReadPageId ?? string.Empty;
-            .Select(u => new { u.LastReadPageId })
-            .FirstOrDefaultAsync(cancellationToken);
-
-        if (user == null)
-        {
-            return Result.Fail<BookConceptsMapResultDto>("User not found.");
-        }
-
-        var lastReadBlockId = user.LastReadPageId ?? string.Empty;
 
         // 2. Fetch all KnowledgeUnits associated with the ebook and user's tenant
-        var units = await dbContext.KnowledgeUnits
+        var units = await _repository.GetKnowledgeUnitsForBookAsync(request.BookId, request.TenantId, cancellationToken);
-            .Where(k => k.EbookId == request.BookId && 
-                       (k.TenantId == request.TenantId || k.TenantId == "global" || string.IsNullOrEmpty(k.TenantId)))
-            .OrderBy(k => k.CreatedAt)
-            .ToListAsync(cancellationToken);
 
         var nodes = new List<GraphNodeDto>();
 
@@ -99,16 +84,9 @@ internal sealed class GetBookConceptsMapQueryHandler : IQueryHandler<GetBookConc
 
         // Return sorted by the numeric value in the seg-ID to ensure topdown vertical alignment
         var sortedNodes = nodes
-            .OrderBy(n => ParseSegmentNumber(n.Id))
+            .OrderBy(n => SegmentIdParser.Parse(n.Id))
             .ToList();
 
         return Result.Ok(new BookConceptsMapResultDto(sortedNodes, lastReadBlockId));
     }
-
-    private static int ParseSegmentNumber(string? id)
-    {
-        if (string.IsNullOrEmpty(id)) return 0;
-        var digits = new string(id.Where(char.IsDigit).ToArray());
-        return int.TryParse(digits, out var val) ? val : 0;
-    }
 }

src/NexusReader.Application/Utilities/SegmentIdParser.cs

@@ -0,0 +1,19 @@
+namespace NexusReader.Application.Utilities;
+
+/// <summary>
+/// Shared utility for parsing numeric segment identifiers from IDs like "seg-42".
+/// Centralizes the parsing contract to avoid duplication across handlers and UI components.
+/// </summary>
+public static class SegmentIdParser
+{
+    /// <summary>
+    /// Extracts the numeric portion from a segment identifier string (e.g., "seg-42" → 42).
+    /// Returns 0 if the string is null, empty, or contains no digits.
+    /// </summary>
+    public static int Parse(string? id)
+    {
+        if (string.IsNullOrEmpty(id)) return 0;
+        var digits = new string(id.Where(char.IsDigit).ToArray());
+        return int.TryParse(digits, out var val) ? val : 0;
+    }
+}

src/NexusReader.Infrastructure/DependencyInjection.cs

@@ -121,6 +121,7 @@ public static class DependencyInjection
         // Fix #1: Ebook repository (scoped, matches AppDbContext lifetime)
         services.AddScoped<IEbookRepository, EbookRepository>();
         services.AddScoped<IQuizResultRepository, QuizResultRepository>();
+        services.AddScoped<IConceptsMapReadRepository, ConceptsMapReadRepository>();
 
         // Fix #2: SignalR broadcaster (scoped, wraps IHubContext which is itself a singleton wrapper)
         services.AddScoped<ISyncBroadcaster, SignalRSyncBroadcaster>();

src/NexusReader.Infrastructure/Persistence/ConceptsMapReadRepository.cs

@@ -0,0 +1,48 @@
+using Microsoft.EntityFrameworkCore;
+using NexusReader.Application.Abstractions.Persistence;
+using NexusReader.Data.Persistence;
+using NexusReader.Domain.Entities;
+
+namespace NexusReader.Infrastructure.Persistence;
+
+/// <summary>
+/// EF Core implementation of <see cref="IConceptsMapReadRepository"/>.
+/// Uses <see cref="IDbContextFactory{TContext}"/> for Blazor-safe scoped context creation.
+/// </summary>
+internal sealed class ConceptsMapReadRepository : IConceptsMapReadRepository
+{
+    private readonly IDbContextFactory<AppDbContext> _dbContextFactory;
+
+    public ConceptsMapReadRepository(IDbContextFactory<AppDbContext> dbContextFactory)
+    {
+        _dbContextFactory = dbContextFactory;
+    }
+
+    /// <inheritdoc />
+    public async Task<string?> GetLastReadPageIdAsync(string userId, CancellationToken cancellationToken = default)
+    {
+        await using var dbContext = await _dbContextFactory.CreateDbContextAsync(cancellationToken);
+
+        var user = await dbContext.Users
+            .Where(u => u.Id == userId)
+            .Select(u => new { u.LastReadPageId })
+            .FirstOrDefaultAsync(cancellationToken);
+
+        return user?.LastReadPageId;
+    }
+
+    /// <inheritdoc />
+    public async Task<List<KnowledgeUnit>> GetKnowledgeUnitsForBookAsync(
+        Guid bookId,
+        string tenantId,
+        CancellationToken cancellationToken = default)
+    {
+        await using var dbContext = await _dbContextFactory.CreateDbContextAsync(cancellationToken);
+
+        return await dbContext.KnowledgeUnits
+            .Where(k => k.EbookId == bookId &&
+                        (k.TenantId == tenantId || k.TenantId == "global" || string.IsNullOrEmpty(k.TenantId)))
+            .OrderBy(k => k.CreatedAt)
+            .ToListAsync(cancellationToken);
+    }
+}

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

@@ -1,4 +1,5 @@
 @using NexusReader.Application.Queries.Graph
+@using NexusReader.Application.Utilities
 @using NexusReader.UI.Shared.Components.Atoms
 
 <div class="concepts-map">
@@ -75,10 +76,10 @@
     {
         if (string.IsNullOrEmpty(nodeId)) return false;
         
-        var nodeSeq = ParseSegmentNumber(nodeId);
+        var nodeSeq = SegmentIdParser.Parse(nodeId);
         
         // Always unlock the very first segment so the user has a starting node
-        var minNodeSeq = Nodes.Any() ? Nodes.Min(n => ParseSegmentNumber(n.Id)) : 0;
+        var minNodeSeq = Nodes.Any() ? Nodes.Min(n => SegmentIdParser.Parse(n.Id)) : 0;
         if (nodeSeq == minNodeSeq) return true;
 
         if (string.IsNullOrEmpty(LastReadBlockId))
@@ -86,16 +87,11 @@
             return false;
         }
 
-        var progressSeq = ParseSegmentNumber(LastReadBlockId);
+        var progressSeq = SegmentIdParser.Parse(LastReadBlockId);
         return nodeSeq <= progressSeq;
     }
 
-    private static int ParseSegmentNumber(string? id)
+
-    {
-        if (string.IsNullOrEmpty(id)) return 0;
-        var digits = new string(id.Where(char.IsDigit).ToArray());
-        return int.TryParse(digits, out var val) ? val : 0;
-    }
 
     private async Task HandleNodeClick(GraphNodeDto node)
     {

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

@@ -65,14 +65,14 @@
 }
 
 .timeline-step.unlocked:hover {
-    border-color: rgba(0, 243, 255, 0.15);
+    border-color: rgba(0, 255, 153, 0.15);
-    box-shadow: 0 4px 20px rgba(0, 243, 255, 0.05);
+    box-shadow: 0 4px 20px rgba(0, 255, 153, 0.05);
 }
 
 .timeline-step.selected {
-    background: rgba(0, 243, 255, 0.04);
+    background: rgba(0, 255, 153, 0.04);
     border-color: var(--nexus-neon);
-    box-shadow: 0 0 15px rgba(0, 243, 255, 0.1);
+    box-shadow: 0 0 15px var(--nexus-primary-glow);
 }
 
 .node-connector-wrapper {
@@ -100,7 +100,7 @@
 .unlocked .node-circle {
     border: 2px solid var(--nexus-neon);
     color: var(--nexus-neon);
-    box-shadow: 0 0 10px rgba(0, 243, 255, 0.3);
+    box-shadow: 0 0 10px var(--nexus-primary-glow);
 }
 
 .locked .node-circle {
@@ -136,8 +136,8 @@
 }
 
 .track-active {
-    background: linear-gradient(180deg, var(--nexus-neon), rgba(0, 243, 255, 0.2));
+    background: linear-gradient(180deg, var(--nexus-neon), rgba(0, 255, 153, 0.2));
-    box-shadow: 0 0 6px rgba(0, 243, 255, 0.2);
+    box-shadow: 0 0 6px var(--nexus-primary-glow);
 }
 
 .track-inactive {
@@ -159,7 +159,7 @@
 
 .timeline-step.selected .node-content {
     background: rgba(255, 255, 255, 0.03);
-    border-color: rgba(0, 243, 255, 0.2);
+    border-color: rgba(0, 255, 153, 0.2);
 }
 
 .node-header {
@@ -188,9 +188,9 @@
 }
 
 .badge-unlocked {
-    background: rgba(0, 243, 255, 0.08);
+    background: rgba(0, 255, 153, 0.08);
     color: var(--nexus-neon);
-    border: 1px solid rgba(0, 243, 255, 0.2);
+    border: 1px solid rgba(0, 255, 153, 0.2);
 }
 
 .badge-locked {

src/NexusReader.UI.Shared/Pages/ConceptsDashboard.razor

@@ -8,12 +8,13 @@
 @using NexusReader.Application.Queries.Concepts
 @using System.Net.Http.Json
 @using NexusReader.Application.Abstractions.Services
+@using NexusReader.Application.Utilities
 @inject IConceptsMapService ConceptsMapService
 @inject NavigationManager NavigationManager
 @inject IIdentityService IdentityService
 @inject ISyncService SyncService
 @attribute [Authorize]
-@implements IDisposable
+@implements IAsyncDisposable
 
 <PageTitle>Mapa Pojęć | Nexus Reader</PageTitle>
 
@@ -235,23 +236,18 @@
     private bool IsUnlocked(string nodeId)
     {
         if (string.IsNullOrEmpty(nodeId)) return false;
-        var nodeSeq = ParseSegmentNumber(nodeId);
+        var nodeSeq = SegmentIdParser.Parse(nodeId);
         
-        var minNodeSeq = Nodes.Any() ? Nodes.Min(n => ParseSegmentNumber(n.Id)) : 0;
+        var minNodeSeq = Nodes.Any() ? Nodes.Min(n => SegmentIdParser.Parse(n.Id)) : 0;
         if (nodeSeq == minNodeSeq) return true;
 
         if (string.IsNullOrEmpty(LastReadBlockId)) return false;
 
-        var progressSeq = ParseSegmentNumber(LastReadBlockId);
+        var progressSeq = SegmentIdParser.Parse(LastReadBlockId);
         return nodeSeq <= progressSeq;
     }
 
-    private static int ParseSegmentNumber(string? id)
+
-    {
-        if (string.IsNullOrEmpty(id)) return 0;
-        var digits = new string(id.Where(char.IsDigit).ToArray());
-        return int.TryParse(digits, out var val) ? val : 0;
-    }
 
     private void HandleNodeSelected(GraphNodeDto node)
     {
@@ -276,7 +272,7 @@
     {
         if (BookId.HasValue && SelectedNode != null)
         {
-            var chapterIndex = ParseSegmentNumber(SelectedNode.Id);
+            var chapterIndex = SegmentIdParser.Parse(SelectedNode.Id);
             NavigationManager.NavigateTo($"/reader/{BookId.Value}?chapter={chapterIndex}");
         }
     }
@@ -299,9 +295,10 @@
         });
     }
 
-    public void Dispose()
+    public ValueTask DisposeAsync()
     {
         IdentityService.OnStateInvalidated -= HandleStateInvalidatedAsync;
         SyncService.OnProgressReceived -= HandleProgressReceivedAsync;
+        return ValueTask.CompletedTask;
     }
 }

src/NexusReader.UI.Shared/Pages/Library.razor.css

@@ -31,7 +31,7 @@
     margin: 0;
 }
 
-::deep .add-book-trigger {
+.add-book-trigger {
     background: var(--nexus-neon) !important;
     color: #000000 !important;
     border: none !important;
@@ -41,7 +41,7 @@
     border-radius: var(--radius-md) !important;
 }
 
-::deep .add-book-trigger:hover {
+.add-book-trigger:hover {
     transform: translateY(-2px) !important;
     box-shadow: 0 8px 20px rgba(0, 255, 153, 0.5) !important;
     filter: brightness(1.1);

src/NexusReader.UI.Shared/Pages/SerilogDemo.razor

@@ -2,13 +2,14 @@
 @inject ILogger<SerilogDemo> Logger
 @inject IJSRuntime JSRuntime
 
+#if DEBUG
 <div class="serilog-demo-container">
     <div class="header-card glass-panel">
         <div class="header-content">
             <NexusIcon Name="cpu" Size="36" Class="header-icon" />
             <div class="header-text">
                 <h1>Serilog Logging Infrastructure</h1>
-                <p class="subtitle">Production-grade diagnostic pipeline for unified native & web logs</p>
+                <p class="subtitle">Production-grade diagnostic pipeline for unified native &amp; web logs</p>
             </div>
         </div>
         <div class="status-badge">
@@ -87,9 +88,18 @@
         </div>
     </div>
 </div>
+#else
+<div class="serilog-demo-container">
+    <div class="glass-panel" style="text-align: center; padding: 3rem;">
+        <h2>Diagnostics Unavailable</h2>
+        <p>This page is only available in DEBUG builds.</p>
+    </div>
+</div>
+#endif
 
 
 @code {
+#if DEBUG
     private void LogInfo()
     {
         Logger.LogInformation("Structured native log triggered by user from SerilogDemo. Button: LogInfo");
@@ -121,4 +131,5 @@
     {
         await JSRuntime.InvokeVoidAsync("eval", "throw new Error('Simulated runtime JS Exception triggered from Blazor UI button click!');");
     }
+#endif
 }

src/NexusReader.UI.Shared/Pages/Settings.razor

@@ -5,13 +5,15 @@
     <h1>Settings</h1>
     <p>Configure your account and application preferences.</p>
 
+    #if DEBUG
     <div class="settings-section glass-panel">
-        <h2>Diagnostics & System Logs</h2>
+        <h2>Diagnostics &amp; System Logs</h2>
         <p>Inspect native logging infrastructure, trigger custom logs, and trace WebView errors.</p>
         <a class="diag-btn" href="/serilog-demo">
             <NexusIcon Name="cpu" Size="16" />
             Open Serilog Diagnostics Dashboard
         </a>
     </div>
+    #endif
 </div>
 

src/NexusReader.UI.Shared/Pages/Settings.razor.css

@@ -5,7 +5,7 @@
     animation: fadeIn 0.6s ease-out;
 }
 
-h1 {
+.settings-page > h1 {
     font-family: var(--nexus-font-serif);
     font-size: 2.8rem;
     font-weight: 700;

src/NexusReader.UI.Shared/wwwroot/app.css

@@ -73,8 +73,13 @@
 .btn-nexus:hover {
     transform: translateY(-2px);
     filter: brightness(1.1);
+}
+.btn-nexus-primary:hover {
     box-shadow: 0 4px 15px var(--nexus-primary-glow);
 }
+.btn-nexus-secondary:hover {
+    box-shadow: 0 4px 15px rgba(255, 255, 255, 0.05);
+}
 
 
 .theme-light {

src/NexusReader.Web/Services/ServerConceptsMapService.cs

@@ -1,8 +1,6 @@
 using System.Security.Claims;
 using FluentResults;
 using MediatR;
-using Microsoft.AspNetCore.Components.Authorization;
-using Microsoft.AspNetCore.Http;
 using NexusReader.Application.Abstractions.Services;
 using NexusReader.Application.Queries.Concepts;
 
@@ -11,38 +9,30 @@ namespace NexusReader.Web.Services;
 public class ServerConceptsMapService : IConceptsMapService
 {
     private readonly IMediator _mediator;
-    private readonly AuthenticationStateProvider _authStateProvider;
+    private readonly IIdentityService _identityService;
-    private readonly IHttpContextAccessor _httpContextAccessor;
 
     public ServerConceptsMapService(
         IMediator mediator,
-        AuthenticationStateProvider authStateProvider,
+        IIdentityService identityService)
-        IHttpContextAccessor httpContextAccessor)
     {
         _mediator = mediator;
-        _authStateProvider = authStateProvider;
+        _identityService = identityService;
-        _httpContextAccessor = httpContextAccessor;
     }
 
     public async Task<Result<BookConceptsMapResultDto>> GetConceptsMapAsync(Guid bookId)
     {
         try
         {
-            var authState = await _authStateProvider.GetAuthenticationStateAsync();
+            var profileResult = await _identityService.GetProfileAsync();
-            var user = authState.User;
-            
-            if (user == null || !user.Identity?.IsAuthenticated == true)
-            {
-                user = _httpContextAccessor.HttpContext?.User;
-            }
 
-            if (user == null || !user.Identity?.IsAuthenticated == true)
+            if (profileResult.IsFailed)
             {
                 return Result.Fail<BookConceptsMapResultDto>("Użytkownik nie jest uwierzytelniony.");
             }
 
-            var userId = user.FindFirstValue(ClaimTypes.NameIdentifier);
+            var profile = profileResult.Value;
-            var tenantId = user.FindFirstValue("TenantId") ?? "global";
+            var userId = profile.UserId;
+            var tenantId = profile.TenantId.ToString();
 
             if (string.IsNullOrEmpty(userId))
             {

src/NexusReader.Web/Services/ServerIdentityService.cs

@@ -114,12 +114,12 @@ public class ServerIdentityService : IIdentityService
         var authState = await _authStateProvider.GetAuthenticationStateAsync();
         var user = authState.User;
         
-        if (user == null || !user.Identity?.IsAuthenticated == true)
+        if (user == null || user.Identity?.IsAuthenticated != true)
         {
             user = _httpContextAccessor.HttpContext?.User;
         }
 
-        if (user == null || !user.Identity?.IsAuthenticated == true) return Result.Fail("Not authenticated.");
+        if (user == null || user.Identity?.IsAuthenticated != true) return Result.Fail("Not authenticated.");
 
         var userId = user.FindFirstValue(ClaimTypes.NameIdentifier);
         if (userId == null) return Result.Fail("User ID not found.");