feat(ui): implement premium NexusSearchBox component and integrate semantic search navigation

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

@@ -1,18 +1,7 @@
 using FluentResults;
 using MediatR;
-using Pgvector;
-using Pgvector.EntityFrameworkCore;
 using NexusReader.Application.Abstractions.Services;
 using NexusReader.Application.DTOs.AI;
-using Microsoft.Extensions.AI;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Resilience;
-using Polly;
-using Polly.Registry;
-using Mapster;
-using MapsterMapper;
-
-using NexusReader.Data.Persistence;
 
 namespace NexusReader.Application.Queries.Library;
 
@@ -21,21 +10,11 @@ public record SearchLibrarySemanticallyQuery(string QueryText, string TenantId,
 
 public class SearchLibrarySemanticallyQueryHandler : IRequestHandler<SearchLibrarySemanticallyQuery, Result<List<SemanticSearchResultDto>>>
 {
-    private readonly IEmbeddingGenerator<string, Embedding<float>> _embeddingGenerator;
-    private readonly IDbContextFactory<AppDbContext> _dbContextFactory;
-    private readonly ResiliencePipeline _retryPipeline;
-    private readonly IMapper _mapper;
+    private readonly IKnowledgeService _knowledgeService;
 
-    public SearchLibrarySemanticallyQueryHandler(
-        IEmbeddingGenerator<string, Embedding<float>> embeddingGenerator,
-        IDbContextFactory<AppDbContext> dbContextFactory,
-        ResiliencePipelineProvider<string> pipelineProvider,
-        IMapper mapper)
+    public SearchLibrarySemanticallyQueryHandler(IKnowledgeService knowledgeService)
     {
-        _embeddingGenerator = embeddingGenerator;
-        _dbContextFactory = dbContextFactory;
-        _retryPipeline = pipelineProvider.GetPipeline("ai-retry");
-        _mapper = mapper;
+        _knowledgeService = knowledgeService;
     }
 
     public async Task<Result<List<SemanticSearchResultDto>>> Handle(SearchLibrarySemanticallyQuery request, CancellationToken cancellationToken)
@@ -45,19 +24,10 @@ public class SearchLibrarySemanticallyQueryHandler : IRequestHandler<SearchLibra
             return Result.Fail("Query text cannot be empty.");
         }
 
-        // Generate embedding with retry
-        var embeddingResponse = await _retryPipeline.ExecuteAsync(async ct =>
-            await _embeddingGenerator.GenerateAsync(new[] { request.QueryText }, cancellationToken: ct), cancellationToken);
-        var queryVector = new Vector(embeddingResponse.First().Vector.ToArray());
-
-        await using var dbContext = await _dbContextFactory.CreateDbContextAsync(cancellationToken);
-        var cacheEntries = await dbContext.SemanticKnowledgeCache
-            .Where(c => c.TenantId == request.TenantId && c.Embedding != null)
-            .OrderBy(c => c.Embedding!.CosineDistance(queryVector))
-            .Take(request.Limit)
-            .ToListAsync(cancellationToken);
-
-        var dtos = _mapper.Map<List<SemanticSearchResultDto>>(cacheEntries);
-        return Result.Ok(dtos);
+        return await _knowledgeService.SearchLibrarySemanticallyAsync(
+            request.QueryText, 
+            request.TenantId, 
+            request.Limit, 
+            cancellationToken);
     }
 }