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

src/NexusReader.Application/Abstractions/Services/IKnowledgeService.cs

@@ -5,10 +5,13 @@ namespace NexusReader.Application.Abstractions.Services;
 
 public interface IKnowledgeService
 {
-    Task<Result<KnowledgePacket>> GetKnowledgeAsync(string text, CancellationToken cancellationToken = default);
-    Task<Result<KnowledgePacket>> GetGraphDataAsync(string text, CancellationToken cancellationToken = default);
-    Task<Result<KnowledgePacket>> GetKnowledgeMapAsync(string text, CancellationToken cancellationToken = default);
-    Task<Result<KnowledgePacket>> GetSummaryAndQuizAsync(string text, CancellationToken cancellationToken = default);
+    Task<Result<KnowledgePacket>> GetKnowledgeAsync(string text, string tenantId, CancellationToken cancellationToken = default);
+    Task<Result<KnowledgePacket>> GetGraphDataAsync(string text, string tenantId, CancellationToken cancellationToken = default);
+    Task<Result<KnowledgePacket>> GetKnowledgeMapAsync(string text, string tenantId, CancellationToken cancellationToken = default);
+    Task<Result<KnowledgePacket>> GetSummaryAndQuizAsync(string text, string tenantId, CancellationToken cancellationToken = default);
     Task<Result<List<RelevantContext>>> GetRelevantContextAsync(string query, string tenantId, CancellationToken cancellationToken = default);
+    Task<Result<GroundednessResult>> VerifyGroundednessAsync(string answer, string context, string tenantId, CancellationToken cancellationToken = default);
     Task<Result> ClearCacheAsync(CancellationToken cancellationToken = default);
 }
+
+public record GroundednessResult(float Score, string Rationale, bool IsGrounded);

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);
     }
 }

src/NexusReader.Application/DependencyInjection.cs

@@ -9,11 +9,8 @@ public static class DependencyInjection
     {
         services.AddMapsterConfiguration();
 
-        services.AddMediatR(config => 
-        {
-            config.RegisterServicesFromAssembly(typeof(DependencyInjection).Assembly);
-        });
-
         return services;
     }
+
+    public static System.Reflection.Assembly Assembly => typeof(DependencyInjection).Assembly;
 }

src/NexusReader.Application/Queries/Graph/GetKnowledgeGraphQuery.cs

@@ -3,5 +3,6 @@ using NexusReader.Application.Abstractions.Messaging;
 namespace NexusReader.Application.Queries.Graph;
 
 /// <param name="Text">Chapter or page content to extract the graph from.</param>
-public record GetKnowledgeGraphQuery(string Text) : IQuery<GraphDataDto>;
+/// <param name="TenantId">Tenant scope for knowledge extraction and caching.</param>
+public record GetKnowledgeGraphQuery(string Text, string TenantId) : IQuery<GraphDataDto>;
 

src/NexusReader.Application/Queries/Graph/GetKnowledgeGraphQueryHandler.cs

@@ -18,20 +18,13 @@ internal sealed class GetKnowledgeGraphQueryHandler : IQueryHandler<GetKnowledge
         if (string.IsNullOrWhiteSpace(request.Text))
             return Result.Ok(new GraphDataDto());
 
-        var result = await _knowledgeService.GetGraphDataAsync(request.Text, cancellationToken);
+        var result = await _knowledgeService.GetGraphDataAsync(request.Text, request.TenantId, cancellationToken);
 
         if (result.IsFailed)
             return Result.Fail<GraphDataDto>(result.Errors);
 
         var graph = result.Value.Graph;
 
-        if (graph is null)
-            return Result.Ok(new GraphDataDto());
-
-        if (graph is null)
-            return Result.Ok(new GraphDataDto());
-            
-        return Result.Ok(graph);
+        return graph is null ? Result.Ok(new GraphDataDto()) : Result.Ok(graph);
     }
 }
-