Stable run with validations

PostFundManagement.Application/Services/Evidence/EvidenceService.cs

@@ -102,6 +102,9 @@ public sealed class EvidenceService(IDbContextFactory<ApplicationDbContext> cont
         {
             await using var context = await contextFactory.CreateDbContextAsync(cancellationToken);
 
+            if (!await context.Users.AnyAsync(u => u.Id == userId, cancellationToken))
+                return Result.Fail(NotFoundError.New);
+
             if (!await context.Projects.AnyAsync(p => p.Id == request.ProjectId, cancellationToken))
                 return Result.Fail(NotFoundError.New);
 
@@ -116,7 +119,7 @@ public sealed class EvidenceService(IDbContextFactory<ApplicationDbContext> cont
                 CreatedAt = DateTime.UtcNow
             });
 
-            return Result.FailIf(await context.SaveChangesAsync(cancellationToken) <= 0, CreateError.New);
+            return Result.FailIf(await context.SaveChangesAsync(cancellationToken) <= 0, CreateError.Create("No record could be created."));
         }));
 
     public async ValueTask<Result> CreateIndicatorAsync(CreateIndicatorRequest request, Guid userId, CancellationToken cancellationToken = default) =>