feat(ingestion): implement hybrid metadata verification form #34 (#41)

### Description
This PR implements **Issue #34: [UI/UX] Implement Hybrid Metadata Verification Form in Ingestion Modal**.

### Key Changes
- **Metadata Verification State**: Introduced a new state in `BookIngestionModal.razor` allowing users to edit `Title` and `Author` before final ingestion.
- **Cover Image Preview**: Added a high-fidelity cover preview with a CSS-based glowing placeholder fallback for books without embedded covers.
- **Ingestion Pipeline**:
  - Implemented `IngestEbookCommand` and `IngestEbookCommandHandler`.
  - Added `IBookStorageService` and its implementation for managing EPUB and cover file storage.
  - Exposed `POST /api/library/ingest` Minimal API endpoint with `.DisableAntiforgery()` to handle client-side JSON uploads.
- **Stability Fixes**:
  - Resolved DI validation errors in the WASM client by providing a dummy `IBookStorageService` registration.
  - Adjusted Kestrel request limits to handle large EPUB payloads (up to 100MB).
  - Corrected middleware ordering to ensure Antiforgery works correctly with Authentication.

### Verification
- Solution builds successfully.
- Manual verification of modal state transitions and API ingestion logic.

Closes #34.

---------

Co-authored-by: Marek Jasiński <jasins.marek@gmail.com>
Reviewed-on: #41
Reviewed-by: Marek Jaisński <jasins.marek@gmail.com>
Co-authored-by: Antigravity <antigravity@google.com>
Co-committed-by: Antigravity <antigravity@google.com>

src/NexusReader.Web/Program.cs

@@ -1,9 +1,11 @@
 using NexusReader.Web.Components;
 using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Components;
 using NexusReader.Application;
 using NexusReader.Infrastructure;
 using NexusReader.Application.Abstractions.Services;
 using NexusReader.Application.Queries.User;
+using NexusReader.Application.Commands.Library;
 using MediatR;
 using NexusReader.Web.Client.Services;
 using NexusReader.UI.Shared.Services;
@@ -48,13 +50,23 @@ builder.Services.AddScoped<IReaderInteractionService, ReaderInteractionService>(
 builder.Services.AddScoped<KnowledgeCoordinator>();
 builder.Services.AddScoped<ISyncService, SyncService>();
 
-builder.Services.AddHttpClient("NexusAPI", client => 
+builder.Services.AddHttpClient("NexusAPI", (sp, client) => 
 {
-    client.BaseAddress = new Uri(builder.Configuration["ApiBaseUrl"] ?? "http://localhost:5000");
+    var configuration = sp.GetRequiredService<IConfiguration>();
+    var apiBaseUrl = configuration["ApiBaseUrl"];
+    if (!string.IsNullOrEmpty(apiBaseUrl))
+    {
+        client.BaseAddress = new Uri(apiBaseUrl);
+    }
+    else
+    {
+        // For local development/Interactive Server, we use the current base address
+        var nav = sp.GetRequiredService<NavigationManager>();
+        client.BaseAddress = new Uri(nav.BaseUri);
+    }
 });
 builder.Services.AddScoped(sp => sp.GetRequiredService<IHttpClientFactory>().CreateClient("NexusAPI"));
 
-builder.Services.AddHttpContextAccessor();
 builder.Services.AddScoped<IIdentityService, NexusReader.Web.Services.ServerIdentityService>();
 builder.Services.AddCascadingAuthenticationState();
 
@@ -220,9 +232,9 @@ if (!app.Environment.IsDevelopment())
     app.UseHttpsRedirection();
 }
 
-app.UseAntiforgery();
 app.UseAuthentication();
 app.UseAuthorization();
+app.UseAntiforgery();
 app.MapStaticAssets();
 app.MapHub<NexusReader.Infrastructure.RealTime.SyncHub>("/synchub");
 
@@ -281,6 +293,30 @@ knowledgeApi.MapDelete("/", async (IKnowledgeService knowledgeService) =>
     return Results.BadRequest(errorMsg);
 });
 
+app.MapPost("/api/library/ingest", async ([FromBody] IngestEbookRequest request, ClaimsPrincipal user, IMediator mediator) =>
+{
+    var userId = user.FindFirstValue(ClaimTypes.NameIdentifier);
+    if (string.IsNullOrEmpty(userId)) return Results.Unauthorized();
+
+    var epubData = Convert.FromBase64String(request.EpubDataBase64);
+    byte[]? coverData = !string.IsNullOrEmpty(request.CoverImageBase64) 
+        ? Convert.FromBase64String(request.CoverImageBase64) 
+        : null;
+
+    var command = new IngestEbookCommand(
+        request.Title,
+        request.AuthorName,
+        coverData,
+        epubData,
+        userId
+    );
+
+    var result = await mediator.Send(command);
+    if (result.IsSuccess) return Results.Ok(new { Id = result.Value });
+
+    return Results.BadRequest(result.Errors.FirstOrDefault()?.Message ?? "Ingestion failed");
+}).RequireAuthorization().DisableAntiforgery();
+
 app.MapPost("/api/StripeWebhook", async (
     HttpContext context, 
     UserManager<NexusUser> userManager,