feat(intelligence): implement Global AI Q&A screen and paywall blocker

- Implemented standard empty and active chat conversation states for the `/intelligence` page
- Created interactive `AiResponseRenderer` with AOT-compliant sentence splitting and payment gateway simulation
- Added scoped `LibraryStateService` to synchronize book ownership and updates across the application
- Obfuscated paywalled content in DOM to prevent inspection bypass
- Fixed local port connection mismatch by updating API configurations to use port 5104

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

@@ -0,0 +1,12 @@
+using System;
+using System.Collections.Generic;
+using NexusReader.Application.DTOs.User;
+
+namespace NexusReader.UI.Shared.Services;
+
+public interface ILibraryStateService
+{
+    List<LastReadBookDto>? OwnedBooks { get; set; }
+    event Action? OnBooksChanged;
+    void NotifyBooksChanged();
+}