Add FluentValidation for ReadResultViewQuery filters

Introduced ReadResultViewQueryValidator to enforce that at least one filter (Id, ActionId, ProfileId, or BatchId) is provided. Also validates that numeric IDs are greater than 0 and BatchId is not empty when present.

src/ReC.Application/Common/Validations/ReadResultViewQueryValidator.cs

@@ -0,0 +1,34 @@
+using FluentValidation;
+using ReC.Application.Results.Queries;
+
+namespace ReC.Application.Common.Validations;
+
+public class ReadResultViewQueryValidator : AbstractValidator<ReadResultViewQuery>
+{
+    public ReadResultViewQueryValidator()
+    {
+        RuleFor(x => x)
+            .Must(x => x.Id.HasValue || x.ActionId.HasValue || x.ProfileId.HasValue || x.BatchId is not null)
+            .WithMessage("At least one filter (Id, ActionId, ProfileId or BatchId) must be provided.");
+
+        RuleFor(x => x.Id)
+            .GreaterThan(0)
+            .When(x => x.Id.HasValue)
+            .WithMessage("Id must be greater than 0.");
+
+        RuleFor(x => x.ActionId)
+            .GreaterThan(0)
+            .When(x => x.ActionId.HasValue)
+            .WithMessage("ActionId must be greater than 0.");
+
+        RuleFor(x => x.ProfileId)
+            .GreaterThan(0)
+            .When(x => x.ProfileId.HasValue)
+            .WithMessage("ProfileId must be greater than 0.");
+
+        RuleFor(x => x.BatchId)
+            .NotEmpty()
+            .When(x => x.BatchId is not null)
+            .WithMessage("BatchId must not be empty when provided.");
+    }
+}