feat(intelligence): implement global hybrid search engine and monetization logic

- Created IUserLibraryStore and IVectorSearchStore abstractions to decouple relational DB and Qdrant gRPC logic from Application Layer
- Implemented MediatR GetGlobalIntelligenceQuery with value-first teaser RAG monetization logic
- Registered new request and response DTOs in AppJsonContext for Native AOT source-generated serialization
- Bound RagMonetizationOptions via IOptions pattern in appsettings.json configuration
- Added POST /api/intelligence endpoint on server and implemented GetGlobalIntelligenceAsync in WASM client service
- Refactored Intelligence.razor to consume the backend-driven global hybrid search Q&A engine

src/NexusReader.Web.Client/Services/WasmKnowledgeService.cs

@@ -2,6 +2,8 @@ using System.Net.Http.Json;
 using FluentResults;
 using NexusReader.Application.Abstractions.Services;
 using NexusReader.Application.DTOs.AI;
+using NexusReader.Application.Common;
+using NexusReader.Application.Queries.Intelligence;
 
 namespace NexusReader.Web.Client.Services;
 
@@ -113,6 +115,34 @@ public class WasmKnowledgeService : IKnowledgeService
         }
     }
 
+    public async Task<Result<IntelligenceResponse>> GetGlobalIntelligenceAsync(string queryText, string userId, string tenantId, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            var response = await _httpClient.PostAsJsonAsync(
+                "/api/intelligence", 
+                new GetGlobalIntelligenceRequest(queryText), 
+                AppJsonContext.Default.GetGlobalIntelligenceRequest, 
+                cancellationToken);
+
+            if (response.IsSuccessStatusCode)
+            {
+                var result = await response.Content.ReadFromJsonAsync<IntelligenceResponse>(
+                    AppJsonContext.Default.IntelligenceResponse, 
+                    cancellationToken: cancellationToken);
+
+                return result != null ? Result.Ok(result) : Result.Fail("Failed to deserialize global intelligence response.");
+            }
+
+            var errorBody = await response.Content.ReadAsStringAsync(cancellationToken);
+            return Result.Fail($"Server error ({response.StatusCode}): {errorBody}");
+        }
+        catch (Exception ex)
+        {
+            return Result.Fail(new Error($"Network error: {ex.Message}").CausedBy(ex));
+        }
+    }
+
     private async Task<Result<KnowledgePacket>> CallKnowledgeApiAsync(string endpoint, string text, Guid? ebookId, CancellationToken cancellationToken)
     {
         try