feat: implement multi-tenancy support across knowledge services and normalize TenantId to string type.

src/NexusReader.Application/Commands/AI/VerifyGroundednessCommand.cs

@@ -1,51 +1,22 @@
 using FluentResults;
 using MediatR;
-using Microsoft.Extensions.AI;
+using NexusReader.Application.Abstractions.Services;
 
 namespace NexusReader.Application.Commands.AI;
 
-public record VerifyGroundednessCommand(string Answer, string Context) : IRequest<Result<GroundednessResult>>;
-
-public record GroundednessResult(float Score, string Rationale, bool IsGrounded);
+public record VerifyGroundednessCommand(string Answer, string Context, string TenantId) : IRequest<Result<GroundednessResult>>;
 
 public class VerifyGroundednessCommandHandler : IRequestHandler<VerifyGroundednessCommand, Result<GroundednessResult>>
 {
-    private readonly IChatClient _chatClient;
+    private readonly IKnowledgeService _knowledgeService;
 
-    public VerifyGroundednessCommandHandler(IChatClient chatClient)
+    public VerifyGroundednessCommandHandler(IKnowledgeService knowledgeService)
     {
-        _chatClient = chatClient;
+        _knowledgeService = knowledgeService;
     }
 
     public async Task<Result<GroundednessResult>> Handle(VerifyGroundednessCommand request, CancellationToken cancellationToken)
     {
-        var systemPrompt = @"
-        You are a Fact-Checking AI. Evaluate if the 'Answer' is supported by the 'Context'.
-        Rate the groundedness from 0.0 to 1.0.
-        Return ONLY a JSON object: { ""score"": 0.9, ""rationale"": ""string"", ""isGrounded"": true }
-        ";
-
-        var userPrompt = $"Context: {request.Context}\n\nAnswer: {request.Answer}";
-
-        try
-        {
-            var response = await _chatClient.GetResponseAsync(new List<ChatMessage>
-            {
-                new ChatMessage(ChatRole.System, systemPrompt),
-                new ChatMessage(ChatRole.User, userPrompt)
-            }, cancellationToken: cancellationToken);
-
-            var rawJson = response.Text?.Trim() ?? "{}";
-            // Simple cleanup if needed
-            rawJson = rawJson.Replace("```json", "").Replace("```", "").Trim();
-            
-            var result = System.Text.Json.JsonSerializer.Deserialize<GroundednessResult>(rawJson, new System.Text.Json.JsonSerializerOptions { PropertyNameCaseInsensitive = true });
-            
-            return result != null ? Result.Ok(result) : Result.Fail("Failed to parse groundedness result");
-        }
-        catch (Exception ex)
-        {
-            return Result.Fail(new Error("Failed to verify groundedness").CausedBy(ex));
-        }
+        return await _knowledgeService.VerifyGroundednessAsync(request.Answer, request.Context, request.TenantId, cancellationToken);
     }
 }