.gitignore

@@ -30,3 +30,5 @@ Thumbs.db
 
 .fake
 src/NexusReader.Web/nexus.db
+src/NexusReader.Web/wwwroot/covers/
+src/NexusReader.Web/wwwroot/uploads/

README.md

@@ -0,0 +1,38 @@
+# 📖 Nexus Reader
+
+Nexus Reader is a state-of-the-art, cross-platform Blazor .NET 10 immersive e-book reader, powered by **Native AOT**, **Clean Architecture**, **CQRS**, and interactive **D3.js Relationship Graphs** built on vector-based AI semantics.
+
+---
+
+## ✨ Features & Architecture Highlights
+
+### 📁 Ingestion & Description persistence
+- Extracted and persistent **book descriptions** from EPUB package metadata during book ingestion.
+- The `Description` field propagates cleanly from the `Ebook` entity through Mapster to `LastReadBookDto` and `UserProfileDto`.
+
+### 🔗 Deep-Link Routing
+- Implemented deep-link route activation: `/reader/{bookId}?chapter=N`.
+- Allows instant resume of reading session coordinates and loads the specific chapter chapter directly via URL query parameters.
+
+### 🛡️ Downstream AI Resilience
+- Standard resilience engine in `DependencyInjection.cs` utilizing the **Polly** package (`ai-retry`).
+- Automatically intercepts, handles, and retries on both rate-limits (`429 Too Many Requests`) and downstream capacity overloads (`503 ServiceUnavailable` / `high demand`).
+
+### ⚙️ Concurrent Request Deduplication
+- Multi-client InteractiveAuto Blazor circuit synchronization is backed by a thread-safe active task registry in `KnowledgeService` which ensures that identical concurrent requests await a single shared task instance, eliminating redundant LLM queries.
+
+---
+
+## 🛠️ Build & Verification Gate
+
+Ensure the dotnet workload matches the active SDK, and compile the full solution utilizing:
+
+```bash
+dotnet build NexusReader.slnx --no-restore
+```
+
+Run test suite:
+
+```bash
+dotnet test --no-restore
+```

src/NexusReader.Application/Commands/Library/IngestEbookCommand.cs

@@ -9,6 +9,7 @@ namespace NexusReader.Application.Commands.Library;
 /// <param name="AuthorName">The name of the author.</param>
 /// <param name="CoverImage">The raw bytes of the cover image (optional).</param>
 /// <param name="EpubData">The raw bytes of the EPUB file.</param>
+/// <param name="Description">The description or summary of the book (optional).</param>
 /// <param name="UserId">The ID of the user owning the book.</param>
 /// <param name="TenantId">The tenant ID for multi-tenant isolation. Defaults to "global" for single-tenant or default usage.</param>
 public record IngestEbookCommand(
@@ -16,6 +17,7 @@ public record IngestEbookCommand(
     string AuthorName,
     byte[]? CoverImage,
     byte[] EpubData,
+    string? Description,
     string UserId,
     string TenantId = "global"
 ) : ICommand<Guid>;

src/NexusReader.Application/Commands/Library/IngestEbookCommandHandler.cs

@@ -63,6 +63,7 @@ public class IngestEbookCommandHandler : IRequestHandler<IngestEbookCommand, Res
                 Author = author,
                 FilePath = epubPath,
                 CoverUrl = coverUrl,
+                Description = request.Description,
                 UserId = request.UserId,
                 TenantId = request.TenantId,
                 AddedDate = DateTime.UtcNow

src/NexusReader.Application/Commands/Library/IngestEbookRequest.cs

@@ -4,5 +4,6 @@ public record IngestEbookRequest(
     string Title,
     string AuthorName,
     string? CoverImageBase64,
-    string EpubDataBase64
+    string EpubDataBase64,
+    string? Description = null
 );

src/NexusReader.Application/DTOs/User/UserProfileDto.cs

@@ -37,4 +37,5 @@ public record LastReadBookDto
     public double Progress { get; init; }
     public string? LastChapter { get; init; }
     public int LastChapterIndex { get; init; }
+    public string? Description { get; init; }
 }

src/NexusReader.Application/Mappings/MappingConfig.cs

@@ -13,7 +13,8 @@ public static class MappingConfig
         var config = TypeAdapterConfig.GlobalSettings;
         
         config.NewConfig<NexusUser, UserProfileDto>();
-            // Roles are mapped manually in queries due to Identity structure
+        config.NewConfig<Ebook, LastReadBookDto>()
+            .Map(dest => dest.Description, src => src.Description);
 
         services.AddSingleton(config);
         services.AddScoped<IMapper, ServiceMapper>();
@@ -21,3 +22,4 @@ public static class MappingConfig
         return services;
     }
 }
+

src/NexusReader.Application/Queries/Library/GetMyEbooksQuery.cs

@@ -0,0 +1,46 @@
+using FluentResults;
+using MediatR;
+using Microsoft.EntityFrameworkCore;
+using NexusReader.Application.DTOs.User;
+using NexusReader.Data.Persistence;
+
+namespace NexusReader.Application.Queries.Library;
+
+public record GetMyEbooksQuery(string UserId) : IRequest<Result<List<LastReadBookDto>>>;
+
+public class GetMyEbooksQueryHandler : IRequestHandler<GetMyEbooksQuery, Result<List<LastReadBookDto>>>
+{
+    private readonly IDbContextFactory<AppDbContext> _dbContextFactory;
+
+    public GetMyEbooksQueryHandler(IDbContextFactory<AppDbContext> dbContextFactory)
+    {
+        _dbContextFactory = dbContextFactory;
+    }
+
+    public async Task<Result<List<LastReadBookDto>>> Handle(GetMyEbooksQuery request, CancellationToken cancellationToken)
+    {
+        using var dbContext = await _dbContextFactory.CreateDbContextAsync(cancellationToken);
+        
+        var ebooks = await dbContext.Ebooks
+            .Where(e => e.UserId == request.UserId)
+            .OrderByDescending(e => e.LastReadDate ?? e.AddedDate)
+            .Select(e => new LastReadBookDto
+            {
+                Id = e.Id,
+                Title = e.Title,
+                Author = new AuthorDto 
+                { 
+                    Id = e.Author.Id, 
+                    Name = e.Author.Name 
+                },
+                CoverUrl = e.CoverUrl,
+                Progress = e.Progress,
+                LastChapter = e.LastChapter ?? "Rozpoczynanie...",
+                LastChapterIndex = e.LastChapterIndex,
+                Description = e.Description
+            })
+            .ToListAsync(cancellationToken);
+
+        return Result.Ok(ebooks);
+    }
+}

src/NexusReader.Application/Queries/Library/SearchLibrarySemanticallyQuery.cs

@@ -4,8 +4,8 @@ using MediatR;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.AI;
 using NexusReader.Application.DTOs.AI;
-
 using NexusReader.Data.Persistence;
+using NexusReader.Domain.Entities;
 using Pgvector;
 using Pgvector.EntityFrameworkCore;
 using System.Text.Json;
@@ -38,33 +38,76 @@ public class SearchLibrarySemanticallyQueryHandler : IRequestHandler<SearchLibra
         using var dbContext = _dbContextFactory.CreateDbContext();
         try
         {
-            // 1. Generate embedding for user query
-            var embeddingResponse = await _embeddingGenerator.GenerateAsync(new[] { request.QueryText }, cancellationToken: cancellationToken);
-            var queryVector = new Vector(embeddingResponse.First().Vector.ToArray());
+            // 1. Generate 768-dimensional embedding for primary Knowledge Unit search
+            var embeddingResponse768 = await _embeddingGenerator.GenerateAsync(
+                new[] { request.QueryText }, 
+                new EmbeddingGenerationOptions { Dimensions = 768 }, 
+                cancellationToken: cancellationToken);
+            var queryVector768 = new Vector(embeddingResponse768.First().Vector.ToArray());
 
             // 2. Perform Cosine Similarity Search on Knowledge Units
-            var candidates = await dbContext.KnowledgeUnits
-                .AsNoTracking()
-                .Where(x => (x.TenantId == request.TenantId || x.TenantId == "global") && x.Vector != null)
-                .OrderBy(x => x.Vector!.CosineDistance(queryVector))
-                .Take(request.Limit)
-                .ToListAsync(cancellationToken);
+            List<KnowledgeUnit> candidates;
+            bool isSqlite = dbContext.Database.ProviderName == "Microsoft.EntityFrameworkCore.Sqlite";
+
+            if (isSqlite)
+            {
+                var allUnits = await dbContext.KnowledgeUnits
+                    .AsNoTracking()
+                    .Where(x => (x.TenantId == request.TenantId || x.TenantId == "global") && x.Vector != null)
+                    .ToListAsync(cancellationToken);
+
+                candidates = allUnits
+                    .OrderBy(x => CalculateCosineDistance(x.Vector!, queryVector768))
+                    .Take(request.Limit)
+                    .ToList();
+            }
+            else
+            {
+                candidates = await dbContext.KnowledgeUnits
+                    .AsNoTracking()
+                    .Where(x => (x.TenantId == request.TenantId || x.TenantId == "global") && x.Vector != null)
+                    .OrderBy(x => x.Vector!.CosineDistance(queryVector768))
+                    .Take(request.Limit)
+                    .ToListAsync(cancellationToken);
+            }
 
             if (!candidates.Any())
             {
-                // Fallback to legacy cache if no granular units found
-                var legacyResults = await dbContext.SemanticKnowledgeCache
-                    .AsNoTracking()
-                    .Where(x => x.TenantId == request.TenantId && x.Vector != null)
-                    .OrderBy(x => x.Vector!.CosineDistance(queryVector))
-                    .Take(request.Limit)
-                    .ToListAsync(cancellationToken);
+                // 3. Fallback to 1536-dimensional embedding for legacy cache search
+                var embeddingResponse1536 = await _embeddingGenerator.GenerateAsync(
+                    new[] { request.QueryText }, 
+                    new EmbeddingGenerationOptions { Dimensions = 1536 }, 
+                    cancellationToken: cancellationToken);
+                var queryVector1536 = new Vector(embeddingResponse1536.First().Vector.ToArray());
+
+                List<SemanticKnowledgeCache> legacyResults;
+                if (isSqlite)
+                {
+                    var allCache = await dbContext.SemanticKnowledgeCache
+                        .AsNoTracking()
+                        .Where(x => x.TenantId == request.TenantId && x.Vector != null)
+                        .ToListAsync(cancellationToken);
+
+                    legacyResults = allCache
+                        .OrderBy(x => CalculateCosineDistance(x.Vector!, queryVector1536))
+                        .Take(request.Limit)
+                        .ToList();
+                }
+                else
+                {
+                    legacyResults = await dbContext.SemanticKnowledgeCache
+                        .AsNoTracking()
+                        .Where(x => x.TenantId == request.TenantId && x.Vector != null)
+                        .OrderBy(x => x.Vector!.CosineDistance(queryVector1536))
+                        .Take(request.Limit)
+                        .ToListAsync(cancellationToken);
+                }
 
                 return Result.Ok(legacyResults.Select(r => new SemanticSearchResultDto
                 {
                     ContentHash = r.ContentHash,
                     Snippet = r.OriginalText,
-                    RelevanceScore = (float)(1 - r.Vector!.CosineDistance(queryVector))
+                    RelevanceScore = (float)(1 - (isSqlite ? CalculateCosineDistance(r.Vector!, queryVector1536) : r.Vector!.CosineDistance(queryVector1536)))
                 }).ToList());
             }
 
@@ -86,10 +129,10 @@ public class SearchLibrarySemanticallyQueryHandler : IRequestHandler<SearchLibra
             {
                 var dto = new SemanticSearchResultDto
                 {
-                    ContentHash = c.Id,
+                    ContentHash = c.Id.ToString(),
                     Snippet = c.Content,
                     UnitType = c.Type.ToString(),
-                    RelevanceScore = (float)(1 - c.Vector!.CosineDistance(queryVector)),
+                    RelevanceScore = (float)(1 - (isSqlite ? CalculateCosineDistance(c.Vector!, queryVector768) : c.Vector!.CosineDistance(queryVector768))),
                     Metadata = string.IsNullOrEmpty(c.MetadataJson) 
                         ? null 
                         : JsonSerializer.Deserialize<Dictionary<string, object>>(c.MetadataJson)
@@ -115,4 +158,22 @@ public class SearchLibrarySemanticallyQueryHandler : IRequestHandler<SearchLibra
             return Result.Fail(new Error("Failed to perform semantic search").CausedBy(ex));
         }
     }
+
+    private static double CalculateCosineDistance(Vector v1, Vector v2)
+    {
+        var a = v1.ToArray();
+        var b = v2.ToArray();
+        if (a.Length != b.Length) return 1.0;
+        double dotProduct = 0;
+        double l1 = 0;
+        double l2 = 0;
+        for (int i = 0; i < a.Length; i++)
+        {
+            dotProduct += a[i] * b[i];
+            l1 += a[i] * a[i];
+            l2 += b[i] * b[i];
+        }
+        if (l1 == 0 || l2 == 0) return 1.0;
+        return 1.0 - (dotProduct / (Math.Sqrt(l1) * Math.Sqrt(l2)));
+    }
 }

src/NexusReader.Application/Queries/Reader/LocalEpubMetadata.cs

@@ -19,4 +19,9 @@ public record LocalEpubMetadata
     /// The raw bytes of the cover image, if available.
     /// </summary>
     public byte[]? CoverImage { get; set; }
+
+    /// <summary>
+    /// The description or summary of the book.
+    /// </summary>
+    public string? Description { get; set; }
 }

src/NexusReader.Application/Queries/User/GetUserProfileQueryHandler.cs

@@ -47,7 +47,8 @@ public class GetUserProfileQueryHandler : IRequestHandler<GetUserProfileQuery, R
                     CoverUrl = e.CoverUrl,
                     Progress = e.Progress,
                     LastChapter = e.LastChapter ?? "Rozpoczynanie...",
-                    LastChapterIndex = e.LastChapterIndex
+                    LastChapterIndex = e.LastChapterIndex,
+                    Description = e.Description
                 }).FirstOrDefault(),
                 Roles = dbContext.UserRoles
                     .Where(ur => ur.UserId == u.Id)

src/NexusReader.Data/Migrations/AppDbContextModelSnapshot.cs

@@ -189,6 +189,9 @@ namespace NexusReader.Data.Migrations
                     b.Property<string>("CoverUrl")
                         .HasColumnType("text");
 
+                    b.Property<string>("Description")
+                        .HasColumnType("text");
+
                     b.Property<string>("FilePath")
                         .IsRequired()
                         .HasColumnType("text");

src/NexusReader.Data/Persistence/AppDbContext.cs

@@ -1,6 +1,7 @@
 using Microsoft.AspNetCore.Identity.EntityFrameworkCore;
 using Microsoft.EntityFrameworkCore;
 using NexusReader.Domain.Entities;
+using Pgvector;
 
 
 namespace NexusReader.Data.Persistence;
@@ -30,8 +31,6 @@ public class AppDbContext : IdentityDbContext<NexusUser>
     {
         base.OnModelCreating(modelBuilder);
 
-        modelBuilder.HasPostgresExtension("vector");
-
         modelBuilder.Entity<NexusUser>(entity =>
         {
             entity.Property(u => u.LastReadPageId).HasMaxLength(255);
@@ -53,26 +52,59 @@ public class AppDbContext : IdentityDbContext<NexusUser>
             entity.HasIndex(p => p.PlanName).IsUnique();
         });
 
-        modelBuilder.Entity<SemanticKnowledgeCache>(entity =>
+        if (Database.IsSqlite())
         {
-            entity.HasKey(e => e.ContentHash);
-            entity.HasIndex(e => e.ContentHash).IsUnique();
-            entity.HasIndex(e => e.TenantId);
-            entity.Property(e => e.Vector).HasColumnType("vector(1536)");
-        });
+            var vectorConverter = new Microsoft.EntityFrameworkCore.Storage.ValueConversion.ValueConverter<Vector, string>(
+                v => v != null ? string.Join(",", v.ToArray()) : string.Empty,
+                s => !string.IsNullOrEmpty(s) ? new Vector(s.Split(',').Select(float.Parse).ToArray()) : null!
+            );
+            
+            modelBuilder.Entity<SemanticKnowledgeCache>(entity =>
+            {
+                entity.HasKey(e => e.ContentHash);
+                entity.HasIndex(e => e.ContentHash).IsUnique();
+                entity.HasIndex(e => e.TenantId);
+                entity.Property(e => e.Vector).HasConversion(vectorConverter);
+            });
 
-        modelBuilder.Entity<KnowledgeUnit>(entity =>
+            modelBuilder.Entity<KnowledgeUnit>(entity =>
+            {
+                entity.HasKey(e => e.Id);
+                entity.HasIndex(e => e.TenantId);
+                entity.HasIndex(e => e.EbookId);
+                entity.Property(e => e.Vector).HasConversion(vectorConverter);
+
+                entity.HasOne(e => e.Ebook)
+                    .WithMany()
+                    .HasForeignKey(e => e.EbookId)
+                    .OnDelete(DeleteBehavior.Cascade);
+            });
+        }
+        else
         {
-            entity.HasKey(e => e.Id);
-            entity.HasIndex(e => e.TenantId);
-            entity.HasIndex(e => e.EbookId);
-            entity.Property(e => e.Vector).HasColumnType("vector(768)");
+            modelBuilder.HasPostgresExtension("vector");
 
-            entity.HasOne(e => e.Ebook)
-                .WithMany()
-                .HasForeignKey(e => e.EbookId)
-                .OnDelete(DeleteBehavior.Cascade);
-        });
+            modelBuilder.Entity<SemanticKnowledgeCache>(entity =>
+            {
+                entity.HasKey(e => e.ContentHash);
+                entity.HasIndex(e => e.ContentHash).IsUnique();
+                entity.HasIndex(e => e.TenantId);
+                entity.Property(e => e.Vector).HasColumnType("vector(1536)");
+            });
+
+            modelBuilder.Entity<KnowledgeUnit>(entity =>
+            {
+                entity.HasKey(e => e.Id);
+                entity.HasIndex(e => e.TenantId);
+                entity.HasIndex(e => e.EbookId);
+                entity.Property(e => e.Vector).HasColumnType("vector(768)");
+
+                entity.HasOne(e => e.Ebook)
+                    .WithMany()
+                    .HasForeignKey(e => e.EbookId)
+                    .OnDelete(DeleteBehavior.Cascade);
+            });
+        }
 
         modelBuilder.Entity<KnowledgeUnitLink>(entity =>
         {

src/NexusReader.Data/Persistence/Migrations/20260514184243_AddDescriptionToEbook.Designer.cs

@@ -0,0 +1,714 @@
+// <auto-generated />
+using System;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using NexusReader.Data.Persistence;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+using Pgvector;
+
+#nullable disable
+
+namespace NexusReader.Data.Persistence.Migrations
+{
+    [DbContext(typeof(AppDbContext))]
+    [Migration("20260514184243_AddDescriptionToEbook")]
+    partial class AddDescriptionToEbook
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "10.0.7")
+                .HasAnnotation("Relational:MaxIdentifierLength", 63);
+
+            NpgsqlModelBuilderExtensions.HasPostgresExtension(modelBuilder, "vector");
+            NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
+
+            modelBuilder.Entity("Microsoft.AspNetCore.Identity.IdentityRole", b =>
+                {
+                    b.Property<string>("Id")
+                        .HasColumnType("text");
+
+                    b.Property<string>("ConcurrencyStamp")
+                        .IsConcurrencyToken()
+                        .HasColumnType("text");
+
+                    b.Property<string>("Name")
+                        .HasMaxLength(256)
+                        .HasColumnType("character varying(256)");
+
+                    b.Property<string>("NormalizedName")
+                        .HasMaxLength(256)
+                        .HasColumnType("character varying(256)");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("NormalizedName")
+                        .IsUnique()
+                        .HasDatabaseName("RoleNameIndex");
+
+                    b.ToTable("AspNetRoles", (string)null);
+                });
+
+            modelBuilder.Entity("Microsoft.AspNetCore.Identity.IdentityRoleClaim<string>", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int>("Id"));
+
+                    b.Property<string>("ClaimType")
+                        .HasColumnType("text");
+
+                    b.Property<string>("ClaimValue")
+                        .HasColumnType("text");
+
+                    b.Property<string>("RoleId")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("RoleId");
+
+                    b.ToTable("AspNetRoleClaims", (string)null);
+                });
+
+            modelBuilder.Entity("Microsoft.AspNetCore.Identity.IdentityUserClaim<string>", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int>("Id"));
+
+                    b.Property<string>("ClaimType")
+                        .HasColumnType("text");
+
+                    b.Property<string>("ClaimValue")
+                        .HasColumnType("text");
+
+                    b.Property<string>("UserId")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("UserId");
+
+                    b.ToTable("AspNetUserClaims", (string)null);
+                });
+
+            modelBuilder.Entity("Microsoft.AspNetCore.Identity.IdentityUserLogin<string>", b =>
+                {
+                    b.Property<string>("LoginProvider")
+                        .HasColumnType("text");
+
+                    b.Property<string>("ProviderKey")
+                        .HasColumnType("text");
+
+                    b.Property<string>("ProviderDisplayName")
+                        .HasColumnType("text");
+
+                    b.Property<string>("UserId")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.HasKey("LoginProvider", "ProviderKey");
+
+                    b.HasIndex("UserId");
+
+                    b.ToTable("AspNetUserLogins", (string)null);
+                });
+
+            modelBuilder.Entity("Microsoft.AspNetCore.Identity.IdentityUserRole<string>", b =>
+                {
+                    b.Property<string>("UserId")
+                        .HasColumnType("text");
+
+                    b.Property<string>("RoleId")
+                        .HasColumnType("text");
+
+                    b.HasKey("UserId", "RoleId");
+
+                    b.HasIndex("RoleId");
+
+                    b.ToTable("AspNetUserRoles", (string)null);
+                });
+
+            modelBuilder.Entity("Microsoft.AspNetCore.Identity.IdentityUserToken<string>", b =>
+                {
+                    b.Property<string>("UserId")
+                        .HasColumnType("text");
+
+                    b.Property<string>("LoginProvider")
+                        .HasColumnType("text");
+
+                    b.Property<string>("Name")
+                        .HasColumnType("text");
+
+                    b.Property<string>("Value")
+                        .HasColumnType("text");
+
+                    b.HasKey("UserId", "LoginProvider", "Name");
+
+                    b.ToTable("AspNetUserTokens", (string)null);
+                });
+
+            modelBuilder.Entity("NexusReader.Domain.Entities.Author", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int>("Id"));
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasMaxLength(255)
+                        .HasColumnType("character varying(255)");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("Authors");
+                });
+
+            modelBuilder.Entity("NexusReader.Domain.Entities.Ebook", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<DateTime>("AddedDate")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<int>("AuthorId")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("CoverUrl")
+                        .HasColumnType("text");
+
+                    b.Property<string>("Description")
+                        .HasColumnType("text");
+
+                    b.Property<string>("FilePath")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<bool>("IsReadyForReading")
+                        .HasColumnType("boolean");
+
+                    b.Property<string>("LastChapter")
+                        .HasMaxLength(255)
+                        .HasColumnType("character varying(255)");
+
+                    b.Property<int>("LastChapterIndex")
+                        .HasColumnType("integer");
+
+                    b.Property<DateTime?>("LastReadDate")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<double>("Progress")
+                        .HasColumnType("double precision");
+
+                    b.Property<string>("TenantId")
+                        .IsRequired()
+                        .HasMaxLength(128)
+                        .HasColumnType("character varying(128)");
+
+                    b.Property<string>("Title")
+                        .IsRequired()
+                        .HasMaxLength(255)
+                        .HasColumnType("character varying(255)");
+
+                    b.Property<string>("UserId")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("AuthorId");
+
+                    b.HasIndex("TenantId");
+
+                    b.HasIndex("UserId");
+
+                    b.ToTable("Ebooks");
+                });
+
+            modelBuilder.Entity("NexusReader.Domain.Entities.KnowledgeUnit", b =>
+                {
+                    b.Property<string>("Id")
+                        .HasMaxLength(128)
+                        .HasColumnType("character varying(128)");
+
+                    b.Property<string>("Content")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<Guid?>("EbookId")
+                        .HasColumnType("uuid");
+
+                    b.Property<string>("MetadataJson")
+                        .HasColumnType("text");
+
+                    b.Property<string>("TenantId")
+                        .IsRequired()
+                        .HasMaxLength(128)
+                        .HasColumnType("character varying(128)");
+
+                    b.Property<int>("Type")
+                        .HasColumnType("integer");
+
+                    b.Property<Vector>("Vector")
+                        .HasColumnType("vector(768)");
+
+                    b.Property<string>("Version")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("character varying(50)");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("EbookId");
+
+                    b.HasIndex("TenantId");
+
+                    b.ToTable("KnowledgeUnits");
+                });
+
+            modelBuilder.Entity("NexusReader.Domain.Entities.KnowledgeUnitLink", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int>("Id"));
+
+                    b.Property<string>("RelationType")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("character varying(50)");
+
+                    b.Property<string>("SourceUnitId")
+                        .IsRequired()
+                        .HasMaxLength(128)
+                        .HasColumnType("character varying(128)");
+
+                    b.Property<string>("TargetUnitId")
+                        .IsRequired()
+                        .HasMaxLength(128)
+                        .HasColumnType("character varying(128)");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("SourceUnitId");
+
+                    b.HasIndex("TargetUnitId");
+
+                    b.ToTable("KnowledgeUnitLinks");
+                });
+
+            modelBuilder.Entity("NexusReader.Domain.Entities.NexusUser", b =>
+                {
+                    b.Property<string>("Id")
+                        .HasColumnType("text");
+
+                    b.Property<int>("AITokenLimit")
+                        .HasColumnType("integer");
+
+                    b.Property<int>("AITokensUsed")
+                        .HasColumnType("integer");
+
+                    b.Property<int>("AccessFailedCount")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("ConcurrencyStamp")
+                        .IsConcurrencyToken()
+                        .HasColumnType("text");
+
+                    b.Property<string>("DisplayName")
+                        .HasMaxLength(100)
+                        .HasColumnType("character varying(100)");
+
+                    b.Property<string>("Email")
+                        .HasMaxLength(256)
+                        .HasColumnType("character varying(256)");
+
+                    b.Property<bool>("EmailConfirmed")
+                        .HasColumnType("boolean");
+
+                    b.Property<DateTime?>("LastAiActionDate")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<DateTime?>("LastReadAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("LastReadPageId")
+                        .HasMaxLength(255)
+                        .HasColumnType("character varying(255)");
+
+                    b.Property<bool>("LockoutEnabled")
+                        .HasColumnType("boolean");
+
+                    b.Property<DateTimeOffset?>("LockoutEnd")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("NormalizedEmail")
+                        .HasMaxLength(256)
+                        .HasColumnType("character varying(256)");
+
+                    b.Property<string>("NormalizedUserName")
+                        .HasMaxLength(256)
+                        .HasColumnType("character varying(256)");
+
+                    b.Property<string>("PasswordHash")
+                        .HasColumnType("text");
+
+                    b.Property<string>("PhoneNumber")
+                        .HasColumnType("text");
+
+                    b.Property<bool>("PhoneNumberConfirmed")
+                        .HasColumnType("boolean");
+
+                    b.Property<string>("SecurityStamp")
+                        .HasColumnType("text");
+
+                    b.Property<int>("SubscriptionPlanId")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer")
+                        .HasDefaultValue(1);
+
+                    b.Property<string>("TenantId")
+                        .IsRequired()
+                        .HasMaxLength(128)
+                        .HasColumnType("character varying(128)");
+
+                    b.Property<bool>("TwoFactorEnabled")
+                        .HasColumnType("boolean");
+
+                    b.Property<string>("UserName")
+                        .HasMaxLength(256)
+                        .HasColumnType("character varying(256)");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("NormalizedEmail")
+                        .HasDatabaseName("EmailIndex");
+
+                    b.HasIndex("NormalizedUserName")
+                        .IsUnique()
+                        .HasDatabaseName("UserNameIndex");
+
+                    b.HasIndex("SubscriptionPlanId");
+
+                    b.HasIndex("TenantId");
+
+                    b.ToTable("AspNetUsers", (string)null);
+                });
+
+            modelBuilder.Entity("NexusReader.Domain.Entities.QuizResult", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<DateTime>("CompletedDate")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<int>("Score")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("TenantId")
+                        .IsRequired()
+                        .HasMaxLength(128)
+                        .HasColumnType("character varying(128)");
+
+                    b.Property<string>("Topic")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<int>("TotalQuestions")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("UserId")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("TenantId");
+
+                    b.HasIndex("UserId");
+
+                    b.ToTable("QuizResults");
+                });
+
+            modelBuilder.Entity("NexusReader.Domain.Entities.SemanticKnowledgeCache", b =>
+                {
+                    b.Property<string>("ContentHash")
+                        .HasMaxLength(128)
+                        .HasColumnType("character varying(128)");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("JsonData")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<string>("ModelId")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("character varying(50)");
+
+                    b.Property<string>("OriginalText")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<string>("PromptVersion")
+                        .IsRequired()
+                        .HasMaxLength(10)
+                        .HasColumnType("character varying(10)");
+
+                    b.Property<string>("TenantId")
+                        .IsRequired()
+                        .HasMaxLength(128)
+                        .HasColumnType("character varying(128)");
+
+                    b.Property<Vector>("Vector")
+                        .HasColumnType("vector(1536)");
+
+                    b.HasKey("ContentHash");
+
+                    b.HasIndex("ContentHash")
+                        .IsUnique();
+
+                    b.HasIndex("TenantId");
+
+                    b.ToTable("SemanticKnowledgeCache");
+                });
+
+            modelBuilder.Entity("NexusReader.Domain.Entities.SubscriptionPlan", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int>("Id"));
+
+                    b.Property<int>("AITokenLimit")
+                        .HasColumnType("integer");
+
+                    b.Property<bool>("IsUnlimitedTokens")
+                        .HasColumnType("boolean");
+
+                    b.Property<decimal>("MonthlyPrice")
+                        .HasColumnType("numeric");
+
+                    b.Property<string>("PlanName")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("character varying(50)");
+
+                    b.Property<string>("StripeProductId")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("character varying(50)");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("PlanName")
+                        .IsUnique();
+
+                    b.ToTable("SubscriptionPlans");
+
+                    b.HasData(
+                        new
+                        {
+                            Id = 1,
+                            AITokenLimit = 5000,
+                            IsUnlimitedTokens = false,
+                            MonthlyPrice = 0m,
+                            PlanName = "Free",
+                            StripeProductId = "prod_Free789"
+                        },
+                        new
+                        {
+                            Id = 2,
+                            AITokenLimit = 10000,
+                            IsUnlimitedTokens = false,
+                            MonthlyPrice = 9.99m,
+                            PlanName = "Basic",
+                            StripeProductId = "prod_basic_placeholder"
+                        },
+                        new
+                        {
+                            Id = 3,
+                            AITokenLimit = 50000,
+                            IsUnlimitedTokens = false,
+                            MonthlyPrice = 19.99m,
+                            PlanName = "Pro",
+                            StripeProductId = "prod_pro_placeholder"
+                        },
+                        new
+                        {
+                            Id = 4,
+                            AITokenLimit = 1000000000,
+                            IsUnlimitedTokens = true,
+                            MonthlyPrice = 99.99m,
+                            PlanName = "Enterprise",
+                            StripeProductId = "prod_enterprise_placeholder"
+                        });
+                });
+
+            modelBuilder.Entity("Microsoft.AspNetCore.Identity.IdentityRoleClaim<string>", b =>
+                {
+                    b.HasOne("Microsoft.AspNetCore.Identity.IdentityRole", null)
+                        .WithMany()
+                        .HasForeignKey("RoleId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("Microsoft.AspNetCore.Identity.IdentityUserClaim<string>", b =>
+                {
+                    b.HasOne("NexusReader.Domain.Entities.NexusUser", null)
+                        .WithMany()
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("Microsoft.AspNetCore.Identity.IdentityUserLogin<string>", b =>
+                {
+                    b.HasOne("NexusReader.Domain.Entities.NexusUser", null)
+                        .WithMany()
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("Microsoft.AspNetCore.Identity.IdentityUserRole<string>", b =>
+                {
+                    b.HasOne("Microsoft.AspNetCore.Identity.IdentityRole", null)
+                        .WithMany()
+                        .HasForeignKey("RoleId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("NexusReader.Domain.Entities.NexusUser", null)
+                        .WithMany()
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("Microsoft.AspNetCore.Identity.IdentityUserToken<string>", b =>
+                {
+                    b.HasOne("NexusReader.Domain.Entities.NexusUser", null)
+                        .WithMany()
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("NexusReader.Domain.Entities.Ebook", b =>
+                {
+                    b.HasOne("NexusReader.Domain.Entities.Author", "Author")
+                        .WithMany("Ebooks")
+                        .HasForeignKey("AuthorId")
+                        .OnDelete(DeleteBehavior.Restrict)
+                        .IsRequired();
+
+                    b.HasOne("NexusReader.Domain.Entities.NexusUser", "User")
+                        .WithMany("Ebooks")
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Author");
+
+                    b.Navigation("User");
+                });
+
+            modelBuilder.Entity("NexusReader.Domain.Entities.KnowledgeUnit", b =>
+                {
+                    b.HasOne("NexusReader.Domain.Entities.Ebook", "Ebook")
+                        .WithMany()
+                        .HasForeignKey("EbookId")
+                        .OnDelete(DeleteBehavior.Cascade);
+
+                    b.Navigation("Ebook");
+                });
+
+            modelBuilder.Entity("NexusReader.Domain.Entities.KnowledgeUnitLink", b =>
+                {
+                    b.HasOne("NexusReader.Domain.Entities.KnowledgeUnit", "SourceUnit")
+                        .WithMany("OutgoingLinks")
+                        .HasForeignKey("SourceUnitId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("NexusReader.Domain.Entities.KnowledgeUnit", "TargetUnit")
+                        .WithMany("IncomingLinks")
+                        .HasForeignKey("TargetUnitId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("SourceUnit");
+
+                    b.Navigation("TargetUnit");
+                });
+
+            modelBuilder.Entity("NexusReader.Domain.Entities.NexusUser", b =>
+                {
+                    b.HasOne("NexusReader.Domain.Entities.SubscriptionPlan", "SubscriptionPlan")
+                        .WithMany()
+                        .HasForeignKey("SubscriptionPlanId")
+                        .OnDelete(DeleteBehavior.Restrict)
+                        .IsRequired();
+
+                    b.Navigation("SubscriptionPlan");
+                });
+
+            modelBuilder.Entity("NexusReader.Domain.Entities.QuizResult", b =>
+                {
+                    b.HasOne("NexusReader.Domain.Entities.NexusUser", "User")
+                        .WithMany("QuizResults")
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("User");
+                });
+
+            modelBuilder.Entity("NexusReader.Domain.Entities.Author", b =>
+                {
+                    b.Navigation("Ebooks");
+                });
+
+            modelBuilder.Entity("NexusReader.Domain.Entities.KnowledgeUnit", b =>
+                {
+                    b.Navigation("IncomingLinks");
+
+                    b.Navigation("OutgoingLinks");
+                });
+
+            modelBuilder.Entity("NexusReader.Domain.Entities.NexusUser", b =>
+                {
+                    b.Navigation("Ebooks");
+
+                    b.Navigation("QuizResults");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

src/NexusReader.Data/Persistence/Migrations/20260514184243_AddDescriptionToEbook.cs

@@ -0,0 +1,28 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace NexusReader.Data.Persistence.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddDescriptionToEbook : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<string>(
+                name: "Description",
+                table: "Ebooks",
+                type: "text",
+                nullable: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "Description",
+                table: "Ebooks");
+        }
+    }
+}

src/NexusReader.Domain/Entities/Ebook.cs

@@ -41,6 +41,8 @@ public class Ebook
 
     public int LastChapterIndex { get; set; } = 0;
     
+    public string? Description { get; set; }
+    
     /// <summary>
     /// Gets or sets a value indicating whether the ebook has been processed by the AI ingestion engine
     /// and is ready for reading (Knowledge Units generated).

src/NexusReader.Infrastructure/Configuration/AiSettings.cs

@@ -6,7 +6,7 @@ public class AiSettings
 
     public string ApiKey { get; set; } = string.Empty;
     public string Model { get; set; } = "gemini-1.5-flash";
-    public string EmbeddingModel { get; set; } = "text-embedding-004";
+    public string EmbeddingModel { get; set; } = "gemini-embedding-001";
     
     /// <summary>
     /// Maximum number of tokens allowed for input.

src/NexusReader.Infrastructure/DependencyInjection.cs

@@ -63,7 +63,12 @@ public static class DependencyInjection
             builder.AddRetry(new RetryStrategyOptions
             {
                 ShouldHandle = new PredicateBuilder().Handle<Exception>(ex =>
-                    ex.Message.Contains("429") || ex.Message.Contains("Too Many Requests") || ex.Message.Contains("quota")),
+                    ex.Message.Contains("429") || 
+                    ex.Message.Contains("Too Many Requests") || 
+                    ex.Message.Contains("quota") ||
+                    ex.Message.Contains("503") ||
+                    ex.Message.Contains("ServiceUnavailable") ||
+                    ex.Message.Contains("demand")),
                 BackoffType = DelayBackoffType.Exponential,
                 UseJitter = true,
                 MaxRetryAttempts = aiSettings.RetryAttempts,
@@ -80,7 +85,7 @@ public static class DependencyInjection
         services.AddEmbeddingGenerator(new GeminiEmbeddingGenerator(new GeminiClientOptions
         {
             ApiKey = aiSettings.ApiKey,
-            ModelId = aiSettings.EmbeddingModel ?? "text-embedding-004"
+            ModelId = aiSettings.EmbeddingModel ?? "gemini-embedding-001"
         }));
 
         // Application-layer service implementations

src/NexusReader.Infrastructure/Services/EpubMetadataExtractor.cs

@@ -19,8 +19,9 @@ public class EpubMetadataExtractor : IEpubMetadataExtractor
             using var bookRef = await EpubReader.OpenBookAsync(epubStream);
             var title = bookRef.Title ?? "Unknown Title";
             var author = bookRef.Author ?? "Unknown Author";
+            var description = bookRef.Description;
             byte[]? cover = await bookRef.ReadCoverAsync();
-            return Result.Ok(new LocalEpubMetadata { Title = title, Author = author, CoverImage = cover });
+            return Result.Ok(new LocalEpubMetadata { Title = title, Author = author, CoverImage = cover, Description = description });
         }
         catch (Exception ex)
         {

src/NexusReader.Infrastructure/Services/KnowledgeService.cs

@@ -1,4 +1,5 @@
 using System.Text.Json;
+using System.Collections.Concurrent;
 using FluentResults;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.AI;
@@ -29,7 +30,8 @@ public class KnowledgeService : IKnowledgeService
     private readonly AiSettings _settings;
     private readonly Tokenizer _tokenizer;
     private readonly ILogger<KnowledgeService> _logger;
-    private const string PromptVersion = "1.0";
+    private const string PromptVersion = "1.3";
+    private static readonly ConcurrentDictionary<string, Task<Result<KnowledgePacket>>> _activeRequests = new();
 
     public KnowledgeService(
         IChatClient chatClient,
@@ -96,9 +98,27 @@ public class KnowledgeService : IKnowledgeService
             }
         }
 
+        // Deduplicate concurrent active requests for the exact same hash
+        var requestKey = $"{tenantId}:{hash}:{traceType}";
+        var task = _activeRequests.GetOrAdd(requestKey, _ => 
+            ExecuteAiRequestAndCacheAsync(normalizedText, tenantId, systemPrompt, traceType, ebookId, hash));
+
+        return await task;
+    }
+
+    private async Task<Result<KnowledgePacket>> ExecuteAiRequestAndCacheAsync(
+        string normalizedText,
+        string tenantId,
+        string systemPrompt,
+        string traceType,
+        Guid? ebookId,
+        string hash)
+    {
         _logger.LogInformation("[KnowledgeService] Cache Miss for {TraceType} ({Hash}). Requesting AI...", traceType, hash);
         try
         {
+            using var dbContext = await _dbContextFactory.CreateDbContextAsync();
+
             var options = new ChatOptions
             {
                 Temperature = (float)_settings.Temperature,
@@ -110,7 +130,7 @@ public class KnowledgeService : IKnowledgeService
                 {
                     new ChatMessage(ChatRole.System, systemPrompt),
                     new ChatMessage(ChatRole.User, normalizedText)
-                }, options, cancellationToken: ct), cancellationToken);
+                }, options, cancellationToken: ct));
 
             var rawResponse = response.Text?.Trim() ?? string.Empty;
             if (string.IsNullOrWhiteSpace(rawResponse)) return Result.Fail("AI returned an empty response.");
@@ -129,16 +149,18 @@ public class KnowledgeService : IKnowledgeService
                 try
                 {
                     var embeddingResponse = await _retryPipeline.ExecuteAsync(async ct => 
-                        await _embeddingGenerator.GenerateAsync(new[] { normalizedText }, cancellationToken: ct), cancellationToken);
+                        await _embeddingGenerator.GenerateAsync(new[] { normalizedText }, new EmbeddingGenerationOptions { Dimensions = 1536 }, cancellationToken: ct));
                     vector = embeddingResponse.First().Vector.ToArray();
                 }
                 catch (Exception ex)
                 {
                     _logger.LogWarning(ex, "[KnowledgeService] Embedding generation failed; proceeding without vector.");
-                    // We continue even if embedding fails, as the primary goal was knowledge extraction
                 }
 
                 // 4. Save to Cache
+                var cached = await dbContext.SemanticKnowledgeCache
+                    .FirstOrDefaultAsync(c => c.ContentHash == hash && c.TenantId == tenantId);
+
                 var cacheEntry = new SemanticKnowledgeCache
                 {
                     ContentHash = hash,
@@ -161,9 +183,9 @@ public class KnowledgeService : IKnowledgeService
                 }
 
                 // 5. Process structured KnowledgeUnits (Graph Expansion)
-                await ProcessKnowledgeUnitsAsync(knowledgePacket, tenantId, ebookId, dbContext, cancellationToken);
+                await ProcessKnowledgeUnitsAsync(knowledgePacket, tenantId, ebookId, dbContext, default);
 
-                await dbContext.SaveChangesAsync(cancellationToken);
+                await dbContext.SaveChangesAsync();
                 return Result.Ok(knowledgePacket);
             }
             catch (JsonException ex)
@@ -176,8 +198,14 @@ public class KnowledgeService : IKnowledgeService
         {
             return Result.Fail(new Error("Failed to extract knowledge from AI").CausedBy(ex));
         }
+        finally
+        {
+            var requestKey = $"{tenantId}:{hash}:{traceType}";
+            _activeRequests.TryRemove(requestKey, out _);
+        }
     }
 
+
     private async Task ProcessKnowledgeUnitsAsync(KnowledgePacket packet, string tenantId, Guid? ebookId, AppDbContext dbContext, CancellationToken cancellationToken)
     {
         var unitIds = packet.Units.Select(u => u.Id).ToList();
@@ -217,7 +245,7 @@ public class KnowledgeService : IKnowledgeService
             try
             {
                 var emb = await _retryPipeline.ExecuteAsync(async ct => 
-                    await _embeddingGenerator.GenerateAsync(new[] { unit.Content }, cancellationToken: ct), cancellationToken);
+                    await _embeddingGenerator.GenerateAsync(new[] { unit.Content }, new EmbeddingGenerationOptions { Dimensions = 768 }, cancellationToken: ct), cancellationToken);
                 unit.Vector = new Vector(emb.First().Vector.ToArray());
             }
             catch { /* Ignore embedding errors for now */ }

src/NexusReader.Infrastructure/Services/PromptRegistry.cs

@@ -6,6 +6,7 @@ public static class PromptRegistry
         "You are an expert educator. Analyze the provided text to extract key concepts, generate relevant quizzes, and construct a knowledge graph. " +
         "CRITICAL: Restrict 'concept.label' to a maximum of 3 words (e.g., 'Dependency Injection' instead of full sentences). " +
         "CRITICAL: Extract a MAXIMUM of 15 key concepts/plot points from the text. " +
+        "CRITICAL: Code blocks (e.g., markdown code snippets) must be excluded from the relationship graph, or summarized as a single node (e.g., 'Code Example'). Do NOT create nodes for variables, functions, namespaces, or individual lines of code. " +
         "CRITICAL: Return ONLY a minified JSON object. Do NOT include markdown formatting like ```json or ```. Do NOT include explanations. " +
         "Schema: { " +
         "\"concepts\": [ { \"title\": \"string\", \"description\": \"string\" } ], " +
@@ -14,13 +15,14 @@ public static class PromptRegistry
         "}.";
 
     public const string GraphExtractionPrompt = 
-        "You are an expert at information architecture. Extract key concepts and their relationships from the text to build a knowledge graph. " +
-        "CRITICAL: Restrict 'label' to a maximum of 3 words. " +
-        "CRITICAL: Extract a MAXIMUM of 15 key concepts/plot points and their relationships. " +
-        "CRITICAL: Each paragraph in the user text starts with [ID: some-id]. Use these IDs ONLY for nodes representing the blocks. " +
-        "CRITICAL: All other extracted 'concept' nodes MUST have unique, slug-style IDs based on their labels (e.g., 'dependency-injection'). " +
-        "Include a 'current' node representing the block content itself if applicable. " +
-        "CRITICAL: Limit the result to a MAXIMUM of 15 most relevant connections. " +
+        "You are an expert at information architecture. Extract key concepts and paragraph mappings from the text to build a unified knowledge graph. " +
+        "The input text consists of several paragraphs, each starting with its unique block ID in the format '[ID: seg-X]'. " +
+        "Extract two types of nodes: " +
+        "1. Concept Nodes (group: 'concept'): Extract the main technical concepts discussed (e.g., ID: 'dependency-injection', label: 'Dependency Injection'). Max 10 concepts. Labels must be at most 3 words. " +
+        "2. Block Nodes (group: 'current'): For each paragraph in the input, create a node representing that paragraph where 'id' is the exact block ID (e.g., 'seg-1'), and 'label' is a brief summary of that paragraph's content (max 3 words). " +
+        "CRITICAL: If a paragraph is a code block, represent it as a single block node with label 'Code Example' (group: 'current'). Do NOT extract low-level code elements (like variables, classes, methods, or namespaces) as separate concept nodes. " +
+        "CRITICAL: Connect related concept nodes together, and connect each concept node to the block nodes ('seg-X') where it is discussed. " +
+        "Limit connections to a MAXIMUM of 15 most relevant links. " +
         "Return ONLY minified JSON. Schema: { \"graph\": { \"nodes\": [ { \"id\": \"string\", \"label\": \"string\", \"group\": \"concept|current\" } ], \"links\": [ { \"source\": \"string\", \"target\": \"string\", \"value\": 1 } ] } }";
 
 
@@ -32,6 +34,7 @@ public static class PromptRegistry
         "You are an expert at Knowledge Engineering. Segment the provided text into discrete Knowledge Units. " +
         "Identify 'units' (sections, tables, definitions, rules) and 'links' (how they relate). " +
         "CRITICAL: Units must be granular. " +
+        "CRITICAL: Code blocks must be summarized under the parent unit or represented as a single 'Code Example' unit. Do NOT segment code blocks into granular low-level code details (e.g., classes, variables, parameters). " +
         "Schema: { " +
         "\"units\": [ { \"id\": \"string\", \"type\": \"Section|Table|Definition|Rule\", \"content\": \"string\", \"metadata\": { \"page\": 0 } } ], " +
         "\"links\": [ { \"source\": \"string\", \"target\": \"string\", \"relation\": \"Next|Defines|Contains|References\" } ] " +

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

@@ -55,6 +55,10 @@
                                     <label>Author</label>
                                     <input type="text" class="form-input" @bind="Metadata.Author" placeholder="Enter author name" />
                                 </div>
+                                <div class="form-group">
+                                    <label>Description</label>
+                                    <textarea class="form-input" @bind="Metadata.Description" placeholder="Book description" rows="3"></textarea>
+                                </div>
                             </div>
                         </div>
 
@@ -205,7 +209,8 @@
                 Metadata.Title,
                 Metadata.Author,
                 Metadata.CoverImage != null ? Convert.ToBase64String(Metadata.CoverImage) : null,
-                Convert.ToBase64String(_epubBytes)
+                Convert.ToBase64String(_epubBytes),
+                Metadata.Description
             );
 
             var response = await Http.PostAsJsonAsync("api/library/ingest", request);

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

@@ -0,0 +1,79 @@
+@using NexusReader.Application.DTOs.User
+@using NexusReader.UI.Shared.Components.Atoms
+@inject NavigationManager NavigationManager
+
+<section class="current-reading-card glass-panel">
+    @if (Book != null)
+    {
+        <div class="card-layout">
+            <div class="book-cover">
+                <img src="@(Book.CoverUrl ?? "https://via.placeholder.com/120x180?text=No+Cover")" alt="@Book.Title" />
+            </div>
+            
+            <div class="book-details">
+                <div class="header-info">
+                    <h3 class="book-title">@Book.Title</h3>
+                    <span class="author-name">by @Book.Author.Name</span>
+                </div>
+
+                <div class="chapter-progress">
+                    <div class="progress-header">
+                        <span class="chapter-name">@Book.LastChapter</span>
+                        <span class="percentage">@(Book.Progress.ToString("F0"))%</span>
+                    </div>
+                    <div class="progress-bar-container">
+                        <div class="progress-bar-fill" style="width: @(Book.Progress.ToString("F0"))%"></div>
+                    </div>
+                </div>
+
+                @if (!string.IsNullOrEmpty(Book.Description))
+                {
+                    <p class="book-excerpt">
+                        @Book.Description
+                    </p>
+                }
+                else
+                {
+                    <p class="book-excerpt empty">
+                        Kontynuuj odkrywanie wiedzy w książce "@Book.Title". 
+                        Twój cyfrowy asystent Nexus jest gotowy do analizy kolejnych rozdziałów i generowania interaktywnych map myśli.
+                    </p>
+                }
+
+                <div class="actions">
+                    <button class="btn-nexus outline" @onclick="HandleContinueReading">
+                        Continue Reading
+                        <NexusIcon Name="arrow-right" Size="16" />
+                    </button>
+                </div>
+            </div>
+        </div>
+    }
+    else
+    {
+        <div class="empty-state">
+            <div class="empty-icon">
+                <NexusIcon Name="book-open" Size="48" />
+            </div>
+            <div class="empty-text">
+                <h3>Brak aktywnych lektur</h3>
+                <p>Przejdź do biblioteki, aby rozpocząć przygodę z Nexus Reader.</p>
+            </div>
+            <button class="btn-nexus primary" @onclick='() => NavigationManager.NavigateTo("/library")'>
+                Przejdź do Biblioteki
+            </button>
+        </div>
+    }
+</section>
+
+@code {
+    [Parameter] public LastReadBookDto? Book { get; set; }
+
+    private void HandleContinueReading()
+    {
+        if (Book != null)
+        {
+            NavigationManager.NavigateTo($"/reader/{Book.Id}?chapter={Book.LastChapterIndex}");
+        }
+    }
+}

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

@@ -0,0 +1,201 @@
+.current-reading-card {
+    width: 100%;
+    padding: 2rem;
+    overflow: hidden;
+}
+
+.card-layout {
+    display: flex;
+    gap: 2.5rem;
+    align-items: flex-start;
+}
+
+.book-cover {
+    width: 140px;
+    flex-shrink: 0;
+    position: relative;
+}
+
+.book-cover img {
+    width: 100%;
+    border-radius: 12px;
+    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.4);
+    border: 1px solid rgba(255, 255, 255, 0.1);
+    transition: transform 0.3s ease;
+}
+
+.book-cover:hover img {
+    transform: translateY(-5px);
+}
+
+.book-details {
+    flex: 1;
+    display: flex;
+    flex-direction: column;
+    gap: 1.25rem;
+    min-width: 0; /* Important for ellipsis */
+}
+
+.header-info {
+    display: flex;
+    flex-direction: column;
+    gap: 0.25rem;
+}
+
+.book-title {
+    font-family: var(--nexus-font-serif);
+    font-size: 1.75rem;
+    font-weight: 700;
+    color: #FFFFFF;
+    margin: 0;
+    white-space: nowrap;
+    overflow: hidden;
+    text-overflow: ellipsis;
+}
+
+.author-name {
+    font-size: 0.9rem;
+    color: #A0A0A0;
+    font-weight: 500;
+}
+
+.chapter-progress {
+    display: flex;
+    flex-direction: column;
+    gap: 0.75rem;
+}
+
+.progress-header {
+    display: flex;
+    justify-content: space-between;
+    font-size: 0.85rem;
+    font-weight: 600;
+}
+
+.chapter-name {
+    color: #FFFFFF;
+    white-space: nowrap;
+    overflow: hidden;
+    text-overflow: ellipsis;
+}
+
+.percentage {
+    color: var(--nexus-neon);
+}
+
+.progress-bar-container {
+    height: 6px;
+    background: rgba(255, 255, 255, 0.05);
+    border-radius: 100px;
+    overflow: hidden;
+}
+
+.progress-bar-fill {
+    height: 100%;
+    background: var(--nexus-neon);
+    box-shadow: 0 0 10px rgba(0, 255, 153, 0.4);
+    border-radius: 100px;
+    transition: width 1s cubic-bezier(0.4, 0, 0.2, 1);
+}
+
+.book-excerpt {
+    font-size: 0.95rem;
+    line-height: 1.6;
+    color: #B0B0B0;
+    margin: 0;
+    display: -webkit-box;
+    -webkit-line-clamp: 3;
+    -webkit-box-orient: vertical;
+    overflow: hidden;
+    text-overflow: ellipsis;
+}
+
+.book-excerpt.empty {
+    font-style: italic;
+    opacity: 0.7;
+}
+
+.actions {
+    margin-top: 0.5rem;
+}
+
+.btn-nexus {
+    display: inline-flex;
+    align-items: center;
+    gap: 0.75rem;
+    padding: 0.8rem 1.5rem;
+    border-radius: 8px;
+    font-size: 0.9rem;
+    font-weight: 600;
+    cursor: pointer;
+    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
+    border: none;
+}
+
+.btn-nexus.outline {
+    background: transparent;
+    color: var(--nexus-neon);
+    border: 1px solid rgba(0, 255, 153, 0.3);
+}
+
+.btn-nexus.outline:hover {
+    background: rgba(0, 255, 153, 0.05);
+    border-color: var(--nexus-neon);
+    transform: translateY(-2px);
+    box-shadow: 0 5px 15px rgba(0, 255, 153, 0.1);
+}
+
+.btn-nexus.primary {
+    background: var(--nexus-neon);
+    color: #000;
+}
+
+.btn-nexus.primary:hover {
+    transform: translateY(-2px);
+    filter: brightness(1.1);
+    box-shadow: 0 5px 15px rgba(0, 255, 153, 0.2);
+}
+
+/* Empty State */
+.empty-state {
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    justify-content: center;
+    gap: 1.5rem;
+    padding: 2rem;
+    text-align: center;
+}
+
+.empty-icon {
+    color: var(--nexus-neon);
+    opacity: 0.3;
+    filter: drop-shadow(0 0 10px rgba(0, 255, 153, 0.2));
+}
+
+.empty-text h3 {
+    color: #FFFFFF;
+    margin: 0 0 0.5rem 0;
+}
+
+.empty-text p {
+    color: #A0A0A0;
+    margin: 0;
+}
+
+@media (max-width: 768px) {
+    .card-layout {
+        flex-direction: column;
+        align-items: center;
+        text-align: center;
+        gap: 1.5rem;
+    }
+    
+    .book-title, .chapter-name {
+        white-space: normal;
+    }
+    
+    .header-info, .chapter-progress {
+        align-items: center;
+    }
+}

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

@@ -9,7 +9,7 @@
 @inject IKnowledgeGraphService GraphService
 @inject IReaderInteractionService InteractionService
 
-<div class="knowledge-graph-container" id="@ContainerId">
+<div class="knowledge-graph-container @(GraphService.IsLoading ? "loading" : "")" id="@ContainerId">
     @if (GraphService.IsLoading || GraphService.CurrentGraphData == null)
     {
         <div class="loading-state">

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

@@ -10,6 +10,10 @@
     position: relative;
 }
 
+.knowledge-graph-container.loading > ::deep svg {
+    display: none !important;
+}
+
 .graph-controls {
     position: absolute;
     bottom: 1.5rem;
@@ -52,12 +56,27 @@
 }
 
 .loading-state {
+    position: absolute;
+    top: 50%;
+    left: 50%;
+    transform: translate(-50%, -50%);
     display: flex;
     flex-direction: column;
     align-items: center;
-    gap: 1.5rem;
+    justify-content: center;
+    gap: 1.25rem;
     color: #fff;
     text-align: center;
+    z-index: 20;
+    background: rgba(13, 13, 13, 0.8);
+    backdrop-filter: blur(8px);
+    padding: 2rem 1.5rem;
+    border-radius: 16px;
+    border: 1px solid rgba(255, 255, 255, 0.05);
+    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.5);
+    width: 85%;
+    max-width: 280px;
+    box-sizing: border-box;
 }
 
 .preloader-robot {

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

@@ -18,13 +18,14 @@
 <div class="reader-canvas @(ThemeService.IsLightMode ? "theme-light" : "theme-dark")">
     @if (ViewModel == null)
     {
-        <div class="loading-state">
-            <NexusTypography Variant="NexusTypography.TypographyVariant.UI">@StatusMessage</NexusTypography>
+        <div class="loading-state full-page">
+            <div class="spinner-glow"></div>
+            <NexusTypography Variant="NexusTypography.TypographyVariant.UI" Class="loading-text">@StatusMessage</NexusTypography>
         </div>
     }
     else
     {
-        <div @ref="_containerRef" class="reader-flow-container">
+        <div @ref="_containerRef" class="reader-flow-container @(_isLoadingChapter ? "content-blurred" : "")">
             @foreach (var block in ViewModel.Blocks)
             {
                 <div id="@block.Id" class="block-wrapper @(_highlightedBlockId == block.Id ? "highlighted" : "")">
@@ -35,6 +36,16 @@
                 </div>
             }
         </div>
+
+        @if (_isLoadingChapter)
+        {
+            <div class="chapter-loading-overlay">
+                <div class="loader-card glass-panel">
+                    <div class="spinner-glow small"></div>
+                    <span class="loader-text">Wczytywanie kolejnego rozdziału...</span>
+                </div>
+            </div>
+        }
     }
 
     <SelectionAiPanel 
@@ -47,6 +58,7 @@
 @code {
     private ReaderPageViewModel? ViewModel;
     private string StatusMessage = "Loading chapter...";
+    private bool _isLoadingChapter;
 
     private string _selectedText = string.Empty;
     private string _selectedBlockId = string.Empty;
@@ -54,6 +66,7 @@
     private string? _highlightedBlockId;
     private bool _isJsInitialized;
     private ElementReference _containerRef;
+    private bool _isInteractive;
 
     protected override async Task OnInitializedAsync()
     {
@@ -86,6 +99,11 @@
         if (firstRender)
         {
             await SyncService.InitializeAsync();
+            _isInteractive = true;
+            if (ViewModel != null)
+            {
+                await Coordinator.ProcessFullPageAsync(GetFullPageContent());
+            }
         }
 
         if (ViewModel != null && !_isJsInitialized)
@@ -193,8 +211,9 @@
 
     private async Task LoadChapterAsync(int index)
     {
-        ViewModel = null;
-        StatusMessage = "Fetching content...";
+        _isLoadingChapter = true;
+        StatusMessage = "Wczytywanie treści...";
+        StateHasChanged();
 
         var authState = await AuthStateProvider.GetAuthenticationStateAsync();
         var userId = authState.User.FindFirst(System.Security.Claims.ClaimTypes.NameIdentifier)?.Value;
@@ -202,7 +221,9 @@
         var ebookId = NavigationService.CurrentEbookId;
         if (ebookId == Guid.Empty)
         {
-            StatusMessage = "No book selected. Please open a book from your library.";
+            ViewModel = null;
+            StatusMessage = "Brak wybranej książki. Otwórz książkę z biblioteki.";
+            _isLoadingChapter = false;
             return;
         }
 
@@ -212,13 +233,20 @@
             ViewModel = result.Value;
             await NavigationService.UpdateMetadataAsync(ViewModel.CurrentChapterIndex, ViewModel.TotalChapters, ViewModel.ChapterTitle);
 
-            await Coordinator.ProcessFullPageAsync(GetFullPageContent());
+            if (_isInteractive)
+            {
+                await Coordinator.ProcessFullPageAsync(GetFullPageContent());
+            }
         }
         else
         {
-            StatusMessage = $"Error: {result.Errors.FirstOrDefault()?.Message ?? "Failed to load"}";
+            ViewModel = null;
+            StatusMessage = $"Błąd: {result.Errors.FirstOrDefault()?.Message ?? "Nie udało się wczytać treści"}";
             Logger.LogError("Failed to load chapter {Index} for ebook {EbookId}: {Errors}", index, ebookId, string.Join(", ", result.Errors.Select(e => e.Message)));
         }
+
+        _isLoadingChapter = false;
+        StateHasChanged();
     }
 
     public async Task ScrollToNodeAsync(string id)

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

@@ -156,4 +156,106 @@
     0% { transform: scale(1); opacity: 1; }
     50% { transform: scale(1.1); opacity: 0.8; }
     100% { transform: scale(1); opacity: 1; }
+}
+
+/* Chapter Loading Overlay and Spinners */
+.loading-state.full-page {
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    justify-content: center;
+    height: 100%;
+    min-height: 400px;
+    gap: 1.5rem;
+    animation: fadeIn 0.4s ease-out;
+}
+
+.spinner-glow {
+    width: 60px;
+    height: 60px;
+    border: 3px solid rgba(0, 255, 153, 0.1);
+    border-radius: 50%;
+    border-top-color: var(--nexus-neon, #00ff99);
+    animation: spin 1s cubic-bezier(0.55, 0.055, 0.675, 0.19) infinite;
+    box-shadow: 0 0 15px rgba(0, 255, 153, 0.2);
+}
+
+.spinner-glow.small {
+    width: 36px;
+    height: 36px;
+    border-width: 2px;
+}
+
+.loading-text {
+    color: rgba(255, 255, 255, 0.7);
+    font-size: 1.1rem;
+    letter-spacing: 0.5px;
+    font-weight: 500;
+}
+
+.theme-light .loading-text {
+    color: rgba(0, 0, 0, 0.7);
+}
+
+.chapter-loading-overlay {
+    position: absolute;
+    top: 0;
+    left: 0;
+    width: 100%;
+    height: 100%;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    z-index: 10;
+    background-color: rgba(15, 23, 42, 0.15);
+    backdrop-filter: blur(2px);
+    animation: fadeIn 0.3s ease-out;
+}
+
+.theme-light .chapter-loading-overlay {
+    background-color: rgba(255, 255, 255, 0.2);
+}
+
+.loader-card {
+    display: flex;
+    align-items: center;
+    gap: 1.25rem;
+    padding: 1.25rem 2rem;
+    border-radius: 40px;
+    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.25), 0 0 1px rgba(255, 255, 255, 0.1) inset;
+    animation: scaleIn 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
+}
+
+.loader-text {
+    font-family: var(--nexus-font-sans, 'Inter', sans-serif);
+    font-weight: 500;
+    color: #ffffff;
+    font-size: 0.95rem;
+    letter-spacing: 0.2px;
+}
+
+.theme-light .loader-text {
+    color: #0f172a;
+}
+
+.content-blurred {
+    filter: blur(3px);
+    opacity: 0.55;
+    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
+    pointer-events: none;
+}
+
+@keyframes spin {
+    0% { transform: rotate(0deg); }
+    100% { transform: rotate(360deg); }
+}
+
+@keyframes scaleIn {
+    from { transform: scale(0.9) translateY(10px); opacity: 0; }
+    to { transform: scale(1) translateY(0); opacity: 1; }
+}
+
+@keyframes fadeIn {
+    from { opacity: 0; }
+    to { opacity: 1; }
 }

src/NexusReader.UI.Shared/Pages/Account/Login.razor

@@ -117,6 +117,7 @@
                 "ProvisioningFailed" => "Wystąpił błąd podczas przygotowywania Twojego konta.",
                 "UserAlreadyExists" => "Użytkownik o tym adresie e-mail już istnieje. Zaloguj się tradycyjnie hasłem.",
                 "LockedOut" => "Twoje konto zostało zablokowane. Spróbuj ponownie później.",
+                "InvalidCredentials" => "Nieprawidłowy e-mail lub hasło.",
                 _ => "Wystąpił nieoczekiwany błąd podczas logowania."
             };
         }
@@ -132,8 +133,8 @@
             var result = await IdentityService.LoginAsync(_loginModel.Email, _loginModel.Password, _loginModel.RememberMe);
             if (result.IsSuccess) 
             {
-                // Trigger hidden form submission to perform cookie-based sign-in
-                await JS.InvokeVoidAsync("eval", "document.getElementById('nexusLoginForm').submit()");
+                // Trigger hidden form submission via robust JS helper to perform cookie-based sign-in
+                await JS.InvokeVoidAsync("nexusAuth.submitLoginForm", "nexusLoginForm", _loginModel.Email, _loginModel.Password, _loginModel.RememberMe);
             }
             else 
             {

src/NexusReader.UI.Shared/Pages/Account/Register.razor

@@ -94,8 +94,8 @@
                 var loginResult = await IdentityService.LoginAsync(_registerModel.Email, _registerModel.Password);
                 if (loginResult.IsSuccess) 
                 {
-                    // Trigger hidden form submission to perform cookie-based sign-in
-                    await JS.InvokeVoidAsync("eval", "document.getElementById('nexusLoginForm').submit()");
+                    // Trigger hidden form submission via robust JS helper to perform cookie-based sign-in
+                    await JS.InvokeVoidAsync("nexusAuth.submitLoginForm", "nexusLoginForm", _registerModel.Email, _registerModel.Password, false);
                 }
                 else 
                 {

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

@@ -1,6 +1,7 @@
 @page "/"
 @using Microsoft.AspNetCore.Authorization
 @using NexusReader.UI.Shared.Components.Atoms
+@using NexusReader.UI.Shared.Components.Organisms
 @using NexusReader.UI.Shared.Services
 @inject IIdentityService IdentityService
 @inject NavigationManager NavigationManager
@@ -42,57 +43,7 @@
         
         <div class="main-grid">
             <!-- Current Reading Card -->
-            <section class="reading-card glass-panel">
-                @if (_profile?.LastReadBook != null)
-                {
-                    <div class="card-header">
-                        <h3>Ostatnio czytane: @_profile.LastReadBook.Title</h3>
-                    </div>
-                    <div class="card-body">
-                        <div class="reading-thumb">
-                            <img src="@(_profile.LastReadBook.CoverUrl ?? "https://upload.wikimedia.org/wikipedia/commons/thumb/e/ec/Mona_Lisa%2C_by_Leonardo_da_Vinci%2C_from_C2RMF_retouched.jpg/402px-Mona_Lisa%2C_by_Leonardo_da_Vinci%2C_from_C2RMF_retouched.jpg")" alt="Current Book" />
-                        </div>
-                        <div class="reading-info">
-                            <div class="progress-section">
-                                <span class="chapter-label">@_profile.LastReadBook.LastChapter</span>
-                                <div class="progress-container">
-                                    <div class="progress-bar" style="width: @(_profile.LastReadBook.Progress.ToString("F0", System.Globalization.CultureInfo.InvariantCulture))%">
-                                        <div class="progress-bubble">@(_profile.LastReadBook.Progress.ToString("F1"))%</div>
-                                    </div>
-                                </div>
-                                <span class="progress-detail">Postęp: @(_profile.LastReadBook.Progress.ToString("F2"))% - @_profile.LastReadBook.Author.Name</span>
-                            </div>
-                            <p class="reading-desc">
-                                Kontynuuj odkrywanie wiedzy w książce "@_profile.LastReadBook.Title". 
-                                Twój cyfrowy asystent Nexus jest gotowy do analizy kolejnych rozdziałów i generowania interaktywnych map myśli.
-                            </p>
-                            <div class="card-actions">
-                                <button class="btn-nexus primary" @onclick='() => NavigationManager.NavigateTo($"/reader?chapter={_profile.LastReadBook.LastChapterIndex}")'>Kontynuuj Czytanie</button>
-                                <button class="btn-nexus secondary" @onclick='() => NavigationManager.NavigateTo("/library")'>Moja Biblioteka</button>
-                            </div>
-                        </div>
-                    </div>
-                }
-                else
-                {
-                    <div class="card-header">
-                        <h3>Brak aktywnych lektur</h3>
-                    </div>
-                    <div class="card-body empty-state">
-                        <div class="empty-icon">
-                            <NexusIcon Name="book-open" Size="64" />
-                        </div>
-                        <div class="reading-info">
-                            <p class="reading-desc">
-                                Nie czytasz obecnie żadnej książki. Przejdź do biblioteki, aby przesłać swój pierwszy plik EPUB i rozpocząć przygodę z Nexus Reader.
-                            </p>
-                            <div class="card-actions">
-                                <button class="btn-nexus primary" @onclick='() => NavigationManager.NavigateTo("/library")'>Przejdź do Biblioteki</button>
-                            </div>
-                        </div>
-                    </div>
-                }
-            </section>
+            <CurrentReadingWidget Book="_profile?.LastReadBook" />
 
             <div class="secondary-grid">
                 <!-- Knowledge Integration -->

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

@@ -1,4 +1,5 @@
 @page "/reader"
+@page "/reader/{BookId:guid}"
 @layout ReaderLayout
 @attribute [Authorize]
 @using NexusReader.UI.Shared.Services
@@ -8,6 +9,7 @@
 @inject IJSRuntime JS
 @inject NavigationManager NavManager
 @inject IReaderNavigationService NavService
+@inject IIdentityService IdentityService
 <PageTitle>Nexus E-Reader</PageTitle>
 
 <div class="home-reader-container">
@@ -16,6 +18,8 @@
 
 
 @code {
+    [Parameter] public Guid? BookId { get; set; }
+
     private ReaderCanvas? readerCanvas;
     private string? _activeQuizBlockId;
     
@@ -28,14 +32,31 @@
         QuizState.OnQuizRequested += HandleQuizRequestedAsync;
         FocusMode.OnFocusModeChanged += HandleUpdate;
         await FocusMode.InitializeAsync();
+    }
 
-        // Handle deep-linking to a specific chapter
+    protected override async Task OnParametersSetAsync()
+    {
         var uri = NavManager.ToAbsoluteUri(NavManager.Uri);
+        int chapterIndex = 0;
         if (Microsoft.AspNetCore.WebUtilities.QueryHelpers.ParseQuery(uri.Query).TryGetValue("chapter", out var chapterValue))
         {
-            if (int.TryParse(chapterValue, out var chapterIndex))
+            int.TryParse(chapterValue, out chapterIndex);
+        }
+
+        if (BookId.HasValue && BookId.Value != Guid.Empty)
+        {
+            if (NavService.CurrentEbookId != BookId.Value || NavService.CurrentChapterIndex != chapterIndex)
             {
-                await NavService.GoToChapter(chapterIndex);
+                NavService.SetBook(BookId.Value, chapterIndex);
+            }
+        }
+        else if (NavService.CurrentEbookId == Guid.Empty)
+        {
+            // If no BookId in URL and no book currently selected, try to load last read book
+            var profileResult = await IdentityService.GetProfileAsync();
+            if (profileResult.IsSuccess && profileResult.Value.LastReadBook != null)
+            {
+                NavService.SetBook(profileResult.Value.LastReadBook.Id, chapterIndex > 0 ? chapterIndex : profileResult.Value.LastReadBook.LastChapterIndex);
             }
         }
     }

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

@@ -1,23 +1,108 @@
 @page "/library"
 @attribute [Authorize]
 @using NexusReader.UI.Shared.Components.Organisms
+@using NexusReader.Application.DTOs.User
+@using NexusReader.UI.Shared.Services
+@using System.Net.Http.Json
+@inject HttpClient Http
+@inject IReaderNavigationService ReaderNavigation
 
 <div class="library-page">
     <header class="library-header">
-        <h1>Biblioteka</h1>
+        <div class="header-title-section">
+            <h1>Moja Biblioteka</h1>
+            <p class="subtitle">Zarządzaj swoją kolekcją e-booków i rozwijaj strukturę wiedzy z Nexus AI</p>
+        </div>
         <AuthorizeView Roles="Admin, ContentManager">
             <NexusButton Class="add-book-trigger" OnClick="() => _isModalOpen = true">
-                [+] Add New Book
+                <span class="btn-icon">+</span> Dodaj E-book
             </NexusButton>
         </AuthorizeView>
     </header>
     
-    <BookIngestionModal @bind-IsOpen="_isModalOpen" />
+    <BookIngestionModal @bind-IsOpen="_isModalOpen" @bind-IsOpen:after="RefreshLibrary" />
     
-    <div class="library-content glass-panel">
-        <div class="empty-state">
-            <p>Twoja kolekcja książek i dokumentów pojawi się tutaj wkrótce.</p>
-        </div>
+    <div class="library-content">
+        @if (_isLoading)
+        {
+            <div class="library-loading-container">
+                <div class="loader-card glass-panel">
+                    <div class="spinner-glow small"></div>
+                    <span class="loader-text">Wczytywanie biblioteki...</span>
+                </div>
+                
+                <div class="loading-grid">
+                    @for (int i = 0; i < 3; i++)
+                    {
+                        <div class="skeleton-card glass-panel">
+                            <div class="skeleton-cover"></div>
+                            <div class="skeleton-details">
+                                <div class="skeleton-line title"></div>
+                                <div class="skeleton-line author"></div>
+                                <div class="skeleton-line progress"></div>
+                            </div>
+                        </div>
+                    }
+                </div>
+            </div>
+        }
+        else if (_books == null || !_books.Any())
+        {
+            <div class="empty-state-container glass-panel">
+                <div class="empty-icon-pulse">
+                    <svg width="64" height="64" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.5" stroke-linecap="round" stroke-linejoin="round">
+                        <path d="M4 19.5A2.5 2.5 0 0 1 6.5 17H20"></path>
+                        <path d="M6.5 2H20v20H6.5A2.5 2.5 0 0 1 4 19.5v-15A2.5 2.5 0 0 1 6.5 2z"></path>
+                    </svg>
+                </div>
+                <h3>Pusta biblioteka</h3>
+                <p>Nie masz jeszcze żadnych książek w swojej kolekcji.</p>
+                <AuthorizeView Roles="Admin, ContentManager">
+                    <Authorized>
+                        <button class="btn-nexus primary" @onclick="() => _isModalOpen = true">
+                            Prześlij pierwszą książkę
+                        </button>
+                    </Authorized>
+                    <NotAuthorized>
+                        <p class="restricted-info">Skontaktuj się z administratorem, aby dodać książki do swojego konta.</p>
+                    </NotAuthorized>
+                </AuthorizeView>
+            </div>
+        }
+        else
+        {
+            <div class="books-grid">
+                @foreach (var book in _books)
+                {
+                    <div class="book-card glass-panel" @onclick="() => OpenBook(book.Id)">
+                        <div class="book-cover-container">
+                            <img src="@(book.CoverUrl ?? "https://api.dicebear.com/7.x/identicon/svg?seed=" + book.Title)" alt="@book.Title" class="book-cover" />
+                            <div class="cover-overlay">
+                                <span class="read-action">Czytaj teraz</span>
+                            </div>
+                        </div>
+                        <div class="book-details">
+                            <h3 class="book-title" title="@book.Title">@book.Title</h3>
+                            <p class="book-author">@book.Author.Name</p>
+                            
+                            @if (book.Progress > 0)
+                            {
+                                <div class="book-progress-section">
+                                    <div class="progress-bar">
+                                        <div class="progress-fill" style="width: @(book.Progress.ToString("F0"))%"></div>
+                                    </div>
+                                    <span class="progress-text">Postęp: @(book.Progress.ToString("F0"))% (@book.LastChapter)</span>
+                                </div>
+                            }
+                            else
+                            {
+                                <span class="new-badge">Nowa</span>
+                            }
+                        </div>
+                    </div>
+                }
+            </div>
+        }
     </div>
 </div>
 
@@ -26,35 +111,440 @@
         padding: 3rem 2rem;
         max-width: 1200px;
         margin: 0 auto;
+        animation: fadeIn 0.6s ease-out;
     }
 
     .library-header {
         display: flex;
         justify-content: space-between;
         align-items: center;
-        margin-bottom: 2.5rem;
+        margin-bottom: 3rem;
+        flex-wrap: wrap;
+        gap: 1.5rem;
     }
 
-    h1 {
-        font-family: var(--nexus-font-serif);
-        font-size: 2.5rem;
+    .header-title-section h1 {
+        font-family: var(--nexus-font-serif, 'Outfit', 'Georgia', serif);
+        font-size: 2.8rem;
+        font-weight: 700;
+        margin: 0 0 0.5rem 0;
+        background: linear-gradient(135deg, var(--nexus-text, #ffffff) 0%, rgba(var(--nexus-text-rgb, 255, 255, 255), 0.7) 100%);
+        -webkit-background-clip: text;
+        -webkit-text-fill-color: transparent;
+        letter-spacing: -0.5px;
+    }
+
+    .header-title-section .subtitle {
+        font-size: 1rem;
+        color: rgba(255, 255, 255, 0.6);
         margin: 0;
-        color: var(--nexus-text);
     }
 
-    .library-content {
-        min-height: 400px;
+    .add-book-trigger {
+        background: linear-gradient(135deg, var(--nexus-primary, #6366f1) 0%, var(--nexus-primary-hover, #4f46e5) 100%) !important;
+        border: none !important;
+        box-shadow: 0 4px 15px rgba(99, 102, 241, 0.4) !important;
+        font-weight: 600 !important;
+        transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1) !important;
+    }
+
+    .add-book-trigger:hover {
+        transform: translateY(-2px) !important;
+        box-shadow: 0 8px 20px rgba(99, 102, 241, 0.6) !important;
+    }
+
+    .btn-icon {
+        margin-right: 0.5rem;
+        font-weight: bold;
+    }
+
+    /* Books Grid */
+    .books-grid, .loading-grid {
+        display: grid;
+        grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
+        gap: 2rem;
+    }
+
+    .book-card {
+        cursor: pointer;
+        display: flex;
+        flex-direction: column;
+        height: 100%;
+        overflow: hidden;
+        border-radius: var(--nexus-radius-lg, 16px);
+        transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
+        position: relative;
+    }
+
+    .book-card::before {
+        content: '';
+        position: absolute;
+        inset: 0;
+        background: radial-gradient(800px circle at var(--x, 0) var(--y, 0), rgba(255, 255, 255, 0.06), transparent 40%);
+        opacity: 0;
+        transition: opacity 0.5s;
+        pointer-events: none;
+    }
+
+    .book-card:hover {
+        transform: translateY(-8px) scale(1.02);
+        box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3), 0 0 2px rgba(255, 255, 255, 0.1) inset;
+        border-color: rgba(255, 255, 255, 0.2);
+    }
+
+    .book-card:hover::before {
+        opacity: 1;
+    }
+
+    .book-cover-container {
+        position: relative;
+        height: 380px;
+        background: rgba(0, 0, 0, 0.2);
+        overflow: hidden;
         display: flex;
         align-items: center;
         justify-content: center;
+        border-bottom: 1px solid rgba(255, 255, 255, 0.05);
     }
 
-    .empty-state {
+    .book-cover {
+        width: 100%;
+        height: 100%;
+        object-fit: cover;
+        transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
+    }
+
+    .book-card:hover .book-cover {
+        transform: scale(1.08);
+    }
+
+    .cover-overlay {
+        position: absolute;
+        inset: 0;
+        background: rgba(15, 23, 42, 0.6);
+        display: flex;
+        align-items: center;
+        justify-content: center;
+        opacity: 0;
+        transition: opacity 0.3s ease;
+        backdrop-filter: blur(4px);
+    }
+
+    .book-card:hover .cover-overlay {
+        opacity: 1;
+    }
+
+    .read-action {
+        color: #ffffff;
+        font-weight: 600;
+        font-size: 1.1rem;
+        padding: 0.75rem 1.5rem;
+        border: 2px solid #ffffff;
+        border-radius: 30px;
+        transform: translateY(10px);
+        transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
+    }
+
+    .book-card:hover .read-action {
+        transform: translateY(0);
+        background: #ffffff;
+        color: #0f172a;
+    }
+
+    .book-details {
+        padding: 1.5rem;
+        display: flex;
+        flex-direction: column;
+        flex-grow: 1;
+        background: rgba(15, 23, 42, 0.3);
+    }
+
+    .book-title {
+        font-size: 1.25rem;
+        font-weight: 600;
+        margin: 0 0 0.5rem 0;
+        color: var(--nexus-text, #ffffff);
+        overflow: hidden;
+        text-overflow: ellipsis;
+        white-space: nowrap;
+        font-family: var(--nexus-font-sans, 'Inter', sans-serif);
+    }
+
+    .book-author {
+        font-size: 0.9rem;
+        color: rgba(255, 255, 255, 0.5);
+        margin: 0 0 1rem 0;
+    }
+
+    .new-badge {
+        align-self: flex-start;
+        font-size: 0.75rem;
+        font-weight: 600;
+        color: var(--nexus-primary, #6366f1);
+        background: rgba(99, 102, 241, 0.15);
+        padding: 0.25rem 0.75rem;
+        border-radius: 20px;
+        border: 1px solid rgba(99, 102, 241, 0.3);
+    }
+
+    /* Book Progress Bar */
+    .book-progress-section {
+        margin-top: auto;
+        display: flex;
+        flex-direction: column;
+        gap: 0.5rem;
+    }
+
+    .progress-bar {
+        height: 6px;
+        background: rgba(255, 255, 255, 0.1);
+        border-radius: 3px;
+        overflow: hidden;
+    }
+
+    .progress-fill {
+        height: 100%;
+        background: linear-gradient(90deg, var(--nexus-primary, #6366f1) 0%, #a855f7 100%);
+        border-radius: 3px;
+    }
+
+    .progress-text {
+        font-size: 0.8rem;
+        color: rgba(255, 255, 255, 0.4);
+        white-space: nowrap;
+        overflow: hidden;
+        text-overflow: ellipsis;
+    }
+
+    /* Empty State */
+    .empty-state-container {
+        display: flex;
+        flex-direction: column;
+        align-items: center;
+        justify-content: center;
+        padding: 5rem 2rem;
         text-align: center;
-        opacity: 0.6;
+        border-radius: var(--nexus-radius-lg, 16px);
+    }
+
+    .empty-icon-pulse {
+        margin-bottom: 2rem;
+        color: rgba(255, 255, 255, 0.2);
+        animation: pulse 3s infinite alternate;
+    }
+
+    .empty-state-container h3 {
+        font-family: var(--nexus-font-serif);
+        font-size: 1.8rem;
+        margin: 0 0 0.5rem 0;
+        color: var(--nexus-text);
+    }
+
+    .empty-state-container p {
+        color: rgba(255, 255, 255, 0.5);
+        max-width: 400px;
+        margin: 0 0 2rem 0;
+    }
+
+    .btn-nexus.primary {
+        background: linear-gradient(135deg, var(--nexus-primary, #6366f1) 0%, var(--nexus-primary-hover, #4f46e5) 100%);
+        color: #ffffff;
+        border: none;
+        padding: 0.75rem 2rem;
+        border-radius: 30px;
+        font-weight: 600;
+        cursor: pointer;
+        box-shadow: 0 4px 15px rgba(99, 102, 241, 0.4);
+        transition: all 0.3s ease;
+    }
+
+    .btn-nexus.primary:hover {
+        transform: translateY(-2px);
+        box-shadow: 0 8px 20px rgba(99, 102, 241, 0.6);
+    }
+
+    .restricted-info {
+        font-size: 0.85rem;
+        font-style: italic;
+        color: rgba(255, 255, 255, 0.35) !important;
+    }
+
+    /* Skeleton Loading */
+    .skeleton-card {
+        border-radius: var(--nexus-radius-lg, 16px);
+        overflow: hidden;
+        height: 480px;
+    }
+
+    .skeleton-cover {
+        height: 380px;
+        background: linear-gradient(90deg, rgba(255,255,255,0.03) 25%, rgba(255,255,255,0.08) 50%, rgba(255,255,255,0.03) 75%);
+        background-size: 200% 100%;
+        animation: loading 1.5s infinite;
+    }
+
+    .skeleton-details {
+        padding: 1.5rem;
+        display: flex;
+        flex-direction: column;
+        gap: 0.75rem;
+    }
+
+    .skeleton-line {
+        background: linear-gradient(90deg, rgba(255,255,255,0.03) 25%, rgba(255,255,255,0.08) 50%, rgba(255,255,255,0.03) 75%);
+        background-size: 200% 100%;
+        animation: loading 1.5s infinite;
+        border-radius: 4px;
+    }
+
+    .skeleton-line.title {
+        height: 20px;
+        width: 80%;
+    }
+
+    .skeleton-line.author {
+        height: 14px;
+        width: 50%;
+    }
+
+    .skeleton-line.progress {
+        height: 8px;
+        width: 100%;
+        margin-top: auto;
+    }
+
+    .library-loading-container {
+        position: relative;
+        width: 100%;
+    }
+
+    .library-loading-container .loader-card {
+        position: absolute;
+        top: 180px;
+        left: 50%;
+        transform: translate(-50%, -50%);
+        z-index: 10;
+        display: flex;
+        align-items: center;
+        gap: 1.25rem;
+        padding: 1.25rem 2.25rem;
+        border-radius: 40px;
+        box-shadow: 0 20px 50px rgba(0, 0, 0, 0.4), 0 0 1px rgba(255, 255, 255, 0.15) inset;
+        background: rgba(15, 23, 42, 0.75);
+        backdrop-filter: blur(16px);
+        border: 1px solid rgba(255, 255, 255, 0.08);
+        animation: scaleIn 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
+    }
+
+    .spinner-glow {
+        width: 60px;
+        height: 60px;
+        border: 3px solid rgba(0, 255, 153, 0.1);
+        border-radius: 50%;
+        border-top-color: var(--nexus-neon, #00ff99);
+        animation: spin 1s cubic-bezier(0.55, 0.055, 0.675, 0.19) infinite;
+        box-shadow: 0 0 15px rgba(0, 255, 153, 0.2);
+    }
+
+    .spinner-glow.small {
+        width: 28px;
+        height: 28px;
+        border-width: 2px;
+    }
+
+    .loader-text {
+        font-family: var(--nexus-font-sans, 'Inter', sans-serif);
+        font-weight: 500;
+        color: #ffffff;
+        font-size: 0.95rem;
+        letter-spacing: 0.2px;
+    }
+
+    /* Skeleton Loading enhancements */
+    .skeleton-card {
+        background: rgba(255, 255, 255, 0.02) !important;
+        border: 1px solid rgba(255, 255, 255, 0.05) !important;
+        box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15) !important;
+        opacity: 0.5;
+    }
+
+    .skeleton-cover {
+        background: linear-gradient(90deg, rgba(255,255,255,0.04) 25%, rgba(255,255,255,0.12) 50%, rgba(255,255,255,0.04) 75%) !important;
+    }
+
+    .skeleton-line {
+        background: linear-gradient(90deg, rgba(255,255,255,0.04) 25%, rgba(255,255,255,0.12) 50%, rgba(255,255,255,0.04) 75%) !important;
+    }
+
+    /* Animations */
+    @@keyframes fadeIn {
+        from { opacity: 0; transform: translateY(15px); }
+        to { opacity: 1; transform: translateY(0); }
+    }
+
+    @@keyframes pulse {
+        0% { transform: scale(0.95); opacity: 0.6; }
+        100% { transform: scale(1.05); opacity: 0.9; }
+    }
+
+    @@keyframes loading {
+        0% { background-position: 200% 0; }
+        100% { background-position: -200% 0; }
+    }
+
+    @@keyframes spin {
+        0% { transform: rotate(0deg); }
+        100% { transform: rotate(360deg); }
+    }
+
+    @@keyframes scaleIn {
+        from { transform: translate(-50%, -50%) scale(0.9); opacity: 0; }
+        to { transform: translate(-50%, -50%) scale(1); opacity: 1; }
     }
 </style>
 
 @code {
     private bool _isModalOpen;
+    private bool _isLoading = true;
+    private List<LastReadBookDto>? _books;
+
+    protected override async Task OnInitializedAsync()
+    {
+        await LoadBooksAsync();
+    }
+
+    private async Task LoadBooksAsync()
+    {
+        _isLoading = true;
+        StateHasChanged();
+        
+        try
+        {
+            _books = await Http.GetFromJsonAsync<List<LastReadBookDto>>("api/library/books");
+            _isLoading = false;
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine($"[Library] Failed to load books: {ex.Message}");
+            if (OperatingSystem.IsBrowser())
+            {
+                _isLoading = false;
+            }
+        }
+        finally
+        {
+            StateHasChanged();
+        }
+    }
+
+    private async Task RefreshLibrary()
+    {
+        // Refresh when modal closes or when a book is successfully ingested
+        await LoadBooksAsync();
+    }
+
+    private void OpenBook(Guid bookId)
+    {
+        ReaderNavigation.NavigateToBook(bookId);
+    }
 }

src/NexusReader.UI.Shared/Services/IReaderNavigationService.cs

@@ -18,4 +18,9 @@ public interface IReaderNavigationService
     /// Navigates to the reader for a specific book and records the current ebook ID.
     /// </summary>
     void NavigateToBook(Guid bookId);
+
+    /// <summary>
+    /// Sets the active book context (ID and optional chapter) without triggering browser routing.
+    /// </summary>
+    void SetBook(Guid bookId, int chapterIndex = 0);
 }

src/NexusReader.UI.Shared/Services/KnowledgeCoordinator.cs

@@ -43,8 +43,34 @@ public sealed partial class KnowledgeCoordinator : IDisposable
 
     private async Task HandleNodeSelected(string nodeId)
     {
-        await _interactionService.RequestScrollToBlock(nodeId);
-        await _interactionService.RequestHighlightBlock(nodeId);
+        string? targetBlockId = nodeId;
+        
+        var graph = _graphService.CurrentGraphData;
+        if (graph != null)
+        {
+            var selectedNode = graph.Nodes.FirstOrDefault(n => n.Id == nodeId);
+            if (selectedNode != null && selectedNode.Group == "concept")
+            {
+                // Look for connected block nodes (group: "current") in the links
+                var connectedLinks = graph.Links.Where(l => l.Source == nodeId || l.Target == nodeId).ToList();
+                foreach (var link in connectedLinks)
+                {
+                    var otherId = link.Source == nodeId ? link.Target : link.Source;
+                    var otherNode = graph.Nodes.FirstOrDefault(n => n.Id == otherId);
+                    if (otherNode != null && otherNode.Group == "current")
+                    {
+                        targetBlockId = otherId;
+                        break;
+                    }
+                }
+            }
+        }
+
+        if (!string.IsNullOrEmpty(targetBlockId))
+        {
+            await _interactionService.RequestScrollToBlock(targetBlockId);
+            await _interactionService.RequestHighlightBlock(targetBlockId);
+        }
     }
 
     public async Task ProcessFullPageAsync(string fullContent, string tenantId = "global")

src/NexusReader.UI.Shared/Services/ReaderNavigationService.cs

@@ -62,6 +62,12 @@ public class ReaderNavigationService : IReaderNavigationService
         _navigationManager.NavigateTo($"/reader/{bookId}");
     }
 
+    public void SetBook(Guid bookId, int chapterIndex = 0)
+    {
+        CurrentEbookId = bookId;
+        CurrentChapterIndex = chapterIndex;
+    }
+
     private async Task NotifyNavigationChangedAsync()
     {
         var handlers = OnNavigationChanged?.GetInvocationList();

src/NexusReader.UI.Shared/wwwroot/js/auth.js

@@ -0,0 +1,17 @@
+window.nexusAuth = {
+    submitLoginForm: function (formId, email, password, rememberMe) {
+        var form = document.getElementById(formId);
+        if (!form) return false;
+        
+        var emailInput = form.querySelector('input[name="email"]');
+        var passwordInput = form.querySelector('input[name="password"]');
+        var rememberMeInput = form.querySelector('input[name="rememberMe"]');
+        
+        if (emailInput) emailInput.value = email;
+        if (passwordInput) passwordInput.value = password;
+        if (rememberMeInput) rememberMeInput.value = rememberMe ? "true" : "false";
+        
+        form.submit();
+        return true;
+    }
+};

src/NexusReader.UI.Shared/wwwroot/js/knowledgeGraph.js

@@ -386,12 +386,19 @@ export function zoomToFit() {
 
 export function clear() {
     if (!rootGroup) return;
-    rootGroup.select(".links-layer").selectAll("path").remove();
-    rootGroup.select(".nodes-layer").selectAll("g.node-group").remove();
-    if (badge) badge.style("display", "none");
-    if (simulation) {
-        simulation.nodes([]);
-        simulation.force("link").links([]);
-        simulation.stop();
+    try {
+        rootGroup.select(".links-layer").selectAll("path").remove();
+        rootGroup.select(".nodes-layer").selectAll("g.node-group").remove();
+        if (badge) badge.style("display", "none");
+        if (simulation) {
+            simulation.stop();
+            const linkForce = simulation.force("link");
+            if (linkForce) {
+                linkForce.links([]);
+            }
+            simulation.nodes([]);
+        }
+    } catch (e) {
+        console.warn("Failed to clear force simulation safely:", e);
     }
 }

src/NexusReader.Web/Components/App.razor

@@ -42,6 +42,7 @@
             setTimeout(hidePreloader, 3000);
         })();
     </script>
+    <script src="_content/NexusReader.UI.Shared/js/auth.js"></script>
 </body>
 
 

src/NexusReader.Web/Program.cs

@@ -6,6 +6,7 @@ using NexusReader.Infrastructure;
 using NexusReader.Application.Abstractions.Services;
 using NexusReader.Application.Queries.User;
 using NexusReader.Application.Commands.Library;
+using NexusReader.Application.Queries.Library;
 using MediatR;
 using NexusReader.Web.Client.Services;
 using NexusReader.UI.Shared.Services;
@@ -235,6 +236,7 @@ if (!app.Environment.IsDevelopment())
     app.UseHttpsRedirection();
 }
 
+app.UseRouting();
 app.UseAuthentication();
 app.UseAuthorization();
 app.UseAntiforgery();
@@ -253,7 +255,9 @@ app.MapGet("/api/epub/{ebookId:guid}/{index:int}", async (Guid ebookId, int inde
     return Results.BadRequest(errorMsg);
 }).RequireAuthorization();
 
-var knowledgeApi = app.MapGroup("/api/knowledge").RequireAuthorization("HasAvailableTokens");
+var knowledgeApi = app.MapGroup("/api/knowledge")
+    .RequireAuthorization("HasAvailableTokens")
+    .DisableAntiforgery();
 
 knowledgeApi.MapPost("/", async (KnowledgeRequest request, ClaimsPrincipal user, IKnowledgeService knowledgeService) =>
 {
@@ -319,6 +323,7 @@ app.MapPost("/api/library/ingest", async ([FromBody] IngestEbookRequest request,
         request.AuthorName,
         coverData,
         epubData,
+        request.Description,
         userId
     );
 
@@ -328,6 +333,18 @@ app.MapPost("/api/library/ingest", async ([FromBody] IngestEbookRequest request,
     return Results.BadRequest(result.Errors.FirstOrDefault()?.Message ?? "Ingestion failed");
 }).RequireAuthorization().DisableAntiforgery();
 
+app.MapGet("/api/library/books", async (ClaimsPrincipal user, IMediator mediator) =>
+{
+    var userId = user.FindFirstValue(ClaimTypes.NameIdentifier);
+    if (string.IsNullOrEmpty(userId)) return Results.Unauthorized();
+
+    var result = await mediator.Send(new GetMyEbooksQuery(userId));
+    if (result.IsSuccess) return Results.Ok(result.Value);
+
+    var errorMsg = result.Errors.Count > 0 ? result.Errors[0].Message : "Unknown server error";
+    return Results.BadRequest(errorMsg);
+}).RequireAuthorization();
+
 app.MapPost("/api/StripeWebhook", async (
     HttpContext context, 
     UserManager<NexusUser> userManager, 
@@ -369,7 +386,7 @@ app.MapPost("/api/StripeWebhook", async (
     {
         return Results.BadRequest(e.Message);
     }
-});
+}).DisableAntiforgery();
 
 async Task HandleSubscriptionSuccess(
     string? email, 

tests/NexusReader.Application.Tests/Queries/QueryTests.cs

@@ -0,0 +1,173 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using FluentAssertions;
+using Microsoft.Data.Sqlite;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.AI;
+using Moq;
+using NexusReader.Application.DTOs.AI;
+using NexusReader.Application.DTOs.User;
+using NexusReader.Application.Queries.Library;
+using NexusReader.Data.Persistence;
+using NexusReader.Domain.Entities;
+using Pgvector;
+using Xunit;
+
+namespace NexusReader.Application.Tests.Queries;
+
+public class QueryTests : IDisposable
+{
+    private readonly SqliteConnection _connection;
+    private readonly DbContextOptions<AppDbContext> _contextOptions;
+    private readonly Mock<IDbContextFactory<AppDbContext>> _dbContextFactoryMock;
+    private readonly Mock<IEmbeddingGenerator<string, Embedding<float>>> _embeddingGeneratorMock;
+
+    public QueryTests()
+    {
+        _connection = new SqliteConnection("DataSource=:memory:");
+        _connection.Open();
+
+        _contextOptions = new DbContextOptionsBuilder<AppDbContext>()
+            .UseSqlite(_connection)
+            .Options;
+
+        // Seed initial database schema
+        using var context = new AppDbContext(_contextOptions);
+        context.Database.EnsureCreated();
+
+        _dbContextFactoryMock = new Mock<IDbContextFactory<AppDbContext>>();
+        _dbContextFactoryMock.Setup(f => f.CreateDbContextAsync(It.IsAny<CancellationToken>()))
+            .ReturnsAsync(() => new AppDbContext(_contextOptions));
+        _dbContextFactoryMock.Setup(f => f.CreateDbContext())
+            .Returns(() => new AppDbContext(_contextOptions));
+
+        _embeddingGeneratorMock = new Mock<IEmbeddingGenerator<string, Embedding<float>>>();
+    }
+
+    [Fact]
+    public async Task GetMyEbooksQuery_WithPopulatedDescription_ReturnsCorrectDescription()
+    {
+        // Arrange
+        using (var context = new AppDbContext(_contextOptions))
+        {
+            var user = new NexusUser
+            {
+                Id = "user-123",
+                UserName = "testuser",
+                Email = "test@example.com",
+                TenantId = "tenant-123",
+                SubscriptionPlanId = 1
+            };
+            context.Users.Add(user);
+
+            var author = new Author { Id = 1, Name = "Adam Mickiewicz" };
+            context.Authors.Add(author);
+
+            var ebook = new Ebook
+            {
+                Id = Guid.NewGuid(),
+                UserId = "user-123",
+                Title = "Pan Tadeusz",
+                AuthorId = author.Id,
+                Description = "A Polish epic poem written by Adam Mickiewicz.",
+                CoverUrl = "cover.png",
+                Progress = 42.5,
+                LastChapter = "Księga I",
+                LastChapterIndex = 1,
+                AddedDate = DateTime.UtcNow,
+                LastReadDate = DateTime.UtcNow,
+                FilePath = "dummy.epub"
+            };
+            context.Ebooks.Add(ebook);
+            await context.SaveChangesAsync();
+        }
+
+        var handler = new GetMyEbooksQueryHandler(_dbContextFactoryMock.Object);
+        var query = new GetMyEbooksQuery("user-123");
+
+        // Act
+        var result = await handler.Handle(query, CancellationToken.None);
+
+        // Assert
+        result.IsSuccess.Should().BeTrue();
+        result.Value.Should().HaveCount(1);
+        result.Value.First().Title.Should().Be("Pan Tadeusz");
+        result.Value.First().Description.Should().Be("A Polish epic poem written by Adam Mickiewicz.");
+        result.Value.First().Progress.Should().Be(42.5);
+    }
+
+    [Fact]
+    public async Task SearchLibrarySemanticallyQuery_WithEmptyQueryText_ReturnsFailure()
+    {
+        // Arrange
+        var handler = new SearchLibrarySemanticallyQueryHandler(_dbContextFactoryMock.Object, _embeddingGeneratorMock.Object);
+        var query = new SearchLibrarySemanticallyQuery("", "tenant-123");
+
+        // Act
+        var result = await handler.Handle(query, CancellationToken.None);
+
+        // Assert
+        result.IsSuccess.Should().BeFalse();
+        result.Errors.First().Message.Should().Be("Query text cannot be empty.");
+    }
+
+    [Fact]
+    public async Task SearchLibrarySemanticallyQuery_WithNoResults_TriggersFallback1536Embedding()
+    {
+        // Arrange
+        // Mock 768-dim primary embedding generator response
+        var embedding768 = new Embedding<float>(new float[768]);
+        var mockResponse768 = new GeneratedEmbeddings<Embedding<float>>(new List<Embedding<float>> { embedding768 });
+        _embeddingGeneratorMock.Setup(g => g.GenerateAsync(
+            It.Is<IEnumerable<string>>(s => s.Contains("test")),
+            It.Is<EmbeddingGenerationOptions>(o => o.Dimensions == 768),
+            It.IsAny<CancellationToken>()))
+            .ReturnsAsync(mockResponse768);
+
+        // Mock 1536-dim fallback embedding generator response
+        var embedding1536 = new Embedding<float>(new float[1536]);
+        var mockResponse1536 = new GeneratedEmbeddings<Embedding<float>>(new List<Embedding<float>> { embedding1536 });
+        _embeddingGeneratorMock.Setup(g => g.GenerateAsync(
+            It.Is<IEnumerable<string>>(s => s.Contains("test")),
+            It.Is<EmbeddingGenerationOptions>(o => o.Dimensions == 1536),
+            It.IsAny<CancellationToken>()))
+            .ReturnsAsync(mockResponse1536);
+
+        // Seed one legacy cache entry
+        using (var context = new AppDbContext(_contextOptions))
+        {
+            var cacheEntry = new SemanticKnowledgeCache
+            {
+                TenantId = "tenant-123",
+                ContentHash = "hash-123",
+                OriginalText = "Fallback Cache Content Snippet",
+                Vector = new Vector(new float[1536]),
+                PromptVersion = "1",
+                CreatedAt = DateTime.UtcNow
+            };
+            context.SemanticKnowledgeCache.Add(cacheEntry);
+            await context.SaveChangesAsync();
+        }
+
+        var handler = new SearchLibrarySemanticallyQueryHandler(_dbContextFactoryMock.Object, _embeddingGeneratorMock.Object);
+        var query = new SearchLibrarySemanticallyQuery("test", "tenant-123");
+
+        // Act
+        var result = await handler.Handle(query, CancellationToken.None);
+
+        // Assert
+        result.IsSuccess.Should().BeTrue();
+        result.Value.Should().HaveCount(1);
+        result.Value.First().Snippet.Should().Be("Fallback Cache Content Snippet");
+        result.Value.First().ContentHash.Should().Be("hash-123");
+    }
+
+    public void Dispose()
+    {
+        _connection.Close();
+        _connection.Dispose();
+    }
+}

tests/NexusReader.Application.Tests/Services/GeminiEmbeddingTests.cs

@@ -0,0 +1,71 @@
+using System;
+using System.Linq;
+using System.Threading.Tasks;
+using FluentAssertions;
+using GeminiDotnet;
+using GeminiDotnet.Extensions.AI;
+using Microsoft.Extensions.AI;
+using Xunit;
+
+namespace NexusReader.Application.Tests.Services;
+
+public class GeminiEmbeddingTests
+{
+    [Fact]
+    public async Task TestGeminiEmbedding_ModelsAndDimensions()
+    {
+        var apiKey = Environment.GetEnvironmentVariable("GEMINI_API_KEY");
+        if (string.IsNullOrEmpty(apiKey))
+        {
+            Console.WriteLine("Skipping test: GEMINI_API_KEY is not set.");
+            return;
+        }
+
+        // Test Model 1: gemini-embedding-001
+        try
+        {
+            var generator = new GeminiEmbeddingGenerator(new GeminiClientOptions
+            {
+                ApiKey = apiKey,
+                ModelId = "gemini-embedding-001"
+            });
+
+            // 1. Without dimensions (default)
+            var responseDefault = await generator.GenerateAsync(new[] { "Hello world" });
+            var vectorDefault = responseDefault.First().Vector.ToArray();
+            Console.WriteLine($"[TEST] gemini-embedding-001 default dimensions: {vectorDefault.Length}");
+
+            // 2. With 768 dimensions
+            var response768 = await generator.GenerateAsync(new[] { "Hello world" }, new EmbeddingGenerationOptions { Dimensions = 768 });
+            var vector768 = response768.First().Vector.ToArray();
+            Console.WriteLine($"[TEST] gemini-embedding-001 768 dimensions: {vector768.Length}");
+
+            // 3. With 1536 dimensions
+            var response1536 = await generator.GenerateAsync(new[] { "Hello world" }, new EmbeddingGenerationOptions { Dimensions = 1536 });
+            var vector1536 = response1536.First().Vector.ToArray();
+            Console.WriteLine($"[TEST] gemini-embedding-001 1536 dimensions: {vector1536.Length}");
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine($"[TEST] gemini-embedding-001 failed: {ex}");
+        }
+
+        // Test Model 2: models/embedding-001
+        try
+        {
+            var generator = new GeminiEmbeddingGenerator(new GeminiClientOptions
+            {
+                ApiKey = apiKey,
+                ModelId = "models/embedding-001"
+            });
+
+            var response = await generator.GenerateAsync(new[] { "Hello world" });
+            var vector = response.First().Vector.ToArray();
+            Console.WriteLine($"[TEST] models/embedding-001 default dimensions: {vector.Length}");
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine($"[TEST] models/embedding-001 failed: {ex}");
+        }
+    }
+}