Make ActionId a required field across DTOs and entities

Updated the `RecActionDto`, `RecAction`, and `InvokeRecActionCommandHandler` to enforce `ActionId` as a required field. This change improves data integrity by removing nullable `ActionId` properties and eliminates the need for null checks or null-forgiveness operators.

src/ReC.Application/Common/Dto/RecActionDto.cs

@@ -2,7 +2,7 @@
 
 public record RecActionDto
 {
-    public long? ActionId { get; init; }
+    public required long ActionId { get; init; }
 
     public long? ProfileId { get; init; }
 

src/ReC.Application/RecActions/Commands/InvokeRecActionCommand.cs

@@ -61,7 +61,7 @@ public class InvokeRecActionCommandHandler(
 
         await sender.Send(new CreateOutResCommand
         {
-            ActionId = (long) request.ActionId!,
+            ActionId = request.ActionId,
             Header = JsonSerializer.Serialize(resHeaders, options: new() { WriteIndented = false }),
             Body = resBody,
             AddedWho = config?["AddedWho"]

src/ReC.Domain/Entities/RecAction.cs

@@ -15,7 +15,7 @@ namespace ReC.Domain.Entities;
 public class RecAction
 {
     [Column("ACTION_ID")]
-    public long? ActionId { get; set; }
+    public required long ActionId { get; set; }
 
     [Column("PROFILE_ID")]
     public long? ProfileId { get; set; }