♻️ Refactor properties in domain models to use auto-implemented properties (#218)

This pull request refactors several domain model classes to simplify
property backing and initialization. The main change is replacing
explicit private backing fields with auto-properties using the `field`
keyword in property setters, which streamlines the code and improves
compatibility with Entity Framework (EF) for object persistence.

### Domain Model Refactoring

* Replaced private backing fields with auto-properties for string
properties in `Hero`, `Power`, `Mission`, `Team`, and `Auditable`
classes. Set default values to `null!` and used the `field` keyword in
property setters for cleaner initialization and EF compatibility.
[[1]](diffhunk://#diff-48e8df39e867e7cb28b51266468197fee05e102ba67af34a8ef0e580076bdf24L14-R37)
[[2]](diffhunk://#diff-fdb830510fd3f05e4ae74b2447761ae2dc7f11124990f4814948e3c9774c7af3L18-R38)
[[3]](diffhunk://#diff-1f2bcbeb7242db733c27dec24dc70710ba549b84e584a02ced4e67b1183539beL9-R29)
[[4]](diffhunk://#diff-e3a277db93c301b96c48a43e832a51d190919c13a640add5ce2da1a8d42916fbL12-R23)
[[5]](diffhunk://#diff-ecb730c8c38c6c6052bf26d059c45ea9498443d3020ef28832feb7504c1d8f44L15-R28)

### Code Clean-up

* Removed unnecessary backing fields from the affected classes, further
simplifying the codebase and reducing redundancy.
[[1]](diffhunk://#diff-48e8df39e867e7cb28b51266468197fee05e102ba67af34a8ef0e580076bdf24L14-R37)
[[2]](diffhunk://#diff-fdb830510fd3f05e4ae74b2447761ae2dc7f11124990f4814948e3c9774c7af3L18-R38)
[[3]](diffhunk://#diff-1f2bcbeb7242db733c27dec24dc70710ba549b84e584a02ced4e67b1183539beL9-R29)
[[4]](diffhunk://#diff-e3a277db93c301b96c48a43e832a51d190919c13a640add5ce2da1a8d42916fbL12-R23)
[[5]](diffhunk://#diff-ecb730c8c38c6c6052bf26d059c45ea9498443d3020ef28832feb7504c1d8f44L15-R28)

### Miscellaneous

* Fixed a minor formatting issue in `Hero.cs` by removing an extraneous
BOM character from the `using` statement.

Author: danielmackay

src/WebApi/Common/Domain/Base/Auditable.cs

@@ -11,32 +11,30 @@ public abstract class Auditable : IAuditable
     public const int UpdatedByMaxLength = 128;
 
     private const string SystemUser = "System";
-    private string _createdBy = null!;
-    private string? _updatedBy;
 
     public DateTimeOffset CreatedAt { get; private set; }
 
     public string CreatedBy
     {
-        get => _createdBy;
+        get;
         private set
         {
             ThrowIfNullOrWhiteSpace(value, nameof(CreatedBy));
             ThrowIfGreaterThan(value.Length, CreatedByMaxLength, nameof(CreatedBy));
-            _createdBy = value;
+            field = value;
         }
-    }
+    } = null!;
 
     public DateTimeOffset? UpdatedAt { get; private set; }
 
     public string? UpdatedBy
     {
-        get => _updatedBy;
+        get;
         private set
         {
             ThrowIfNullOrWhiteSpace(value, nameof(UpdatedBy));
             ThrowIfGreaterThan(value.Length, UpdatedByMaxLength, nameof(UpdatedBy));
-            _updatedBy = value;
+            field = value;
         }
     }
 

src/WebApi/Common/Domain/Heroes/Hero.cs

@@ -1,4 +1,4 @@
-using SSW.VerticalSliceArchitecture.Common.Domain.Base;
+using SSW.VerticalSliceArchitecture.Common.Domain.Base;
 using SSW.VerticalSliceArchitecture.Common.Domain.Teams;
 
 namespace SSW.VerticalSliceArchitecture.Common.Domain.Heroes;
@@ -15,30 +15,27 @@ public class Hero : AggregateRoot<HeroId>
 
     private readonly List<Power> _powers = [];
 
-    private string _name = null!;
-    private string _alias = null!;
-
     public string Name
     {
-        get => _name;
+        get;
         set
         {
             ThrowIfNullOrWhiteSpace(value, nameof(Name));
             ThrowIfGreaterThan(value.Length, NameMaxLength, nameof(Name));
-            _name = value;
+            field = value;
         }
-    }
+    } = null!;
 
     public string Alias
     {
-        get => _alias;
+        get;
         set
         {
             ThrowIfNullOrWhiteSpace(value, nameof(Alias));
             ThrowIfGreaterThan(value.Length, AliasMaxLength, nameof(Alias));
-            _alias = value;
+            field = value;
         }
-    }
+    } = null!;
 
     public int PowerLevel { get; private set; }
     public TeamId? TeamId { get; private set; }

src/WebApi/Common/Domain/Heroes/Power.cs

@@ -6,30 +6,27 @@ public record Power : IValueObject
 {
     public const int NameMaxLength = 50;
 
-    private string _name = null!;
-    private int _powerLevel;
-
     // Private setters needed for EF
     public string Name
     {
-        get => _name;
+        get;
         private set
         {
             ThrowIfNullOrWhiteSpace(value, nameof(Name));
             ThrowIfGreaterThan(value.Length, NameMaxLength, nameof(Name));
-            _name = value;
+            field = value;
         }
-    }
+    } = null!;
 
     // Private setters needed for EF
     public int PowerLevel
     {
-        get => _powerLevel;
+        get;
         private set
         {
             ThrowIfLessThan(value, 1, nameof(PowerLevel));
             ThrowIfGreaterThan(value, 10, nameof(PowerLevel));
-            _powerLevel = value;
+            field = value;
         }
     }
 

src/WebApi/Common/Domain/Teams/Mission.cs

@@ -9,19 +9,18 @@ namespace SSW.VerticalSliceArchitecture.Common.Domain.Teams;
 
 public class Mission : Entity<MissionId>
 {
-    private string _description = null!;
     public const int DescriptionMaxLength = 500;
 
     public string Description
     {
-        get => _description;
+        get;
         private set
         {
             ThrowIfNullOrWhiteSpace(value, nameof(Description));
             ThrowIfGreaterThan(value.Length, DescriptionMaxLength, nameof(Description));
-            _description = value;
+            field = value;
         }
-    }
+    } = null!;
 
     public MissionStatus Status { get; private set; }
 

src/WebApi/Common/Domain/Teams/Team.cs

@@ -12,21 +12,20 @@ public class Team : AggregateRoot<TeamId>
 {
     public const int NameMaxLength = 100;
 
-    private string _name = null!;
     private readonly List<Hero> _heroes = [];
     private readonly List<Mission> _missions = [];
     private Mission? CurrentMission => _missions.FirstOrDefault(m => m.Status == MissionStatus.InProgress);
 
     public string Name
     {
-        get => _name;
+        get;
         private set
         {
             ThrowIfNullOrWhiteSpace(value, nameof(Name));
             ThrowIfGreaterThan(value.Length, NameMaxLength, nameof(Name));
-            _name = value;
+            field = value;
         }
-    }
+    } = null!;
 
     public int TotalPowerLevel { get; private set; }
     public TeamStatus Status { get; private set; }