First couple abilities implemented

PkmnLib.Dynamic/Models/ExecutingMove.cs

@@ -46,6 +46,16 @@ public interface IHitData
     /// Fails the hit.
     /// </summary>
     void Fail();
+
+    /// <summary>
+    /// Sets a flag on the hit data. This is used to mark certain conditions or states
+    /// </summary>
+    void SetFlag(StringKey flag);
+
+    /// <summary>
+    /// Checks whether a flag is set on the hit data.
+    /// </summary>
+    bool HasFlag(StringKey flag);
 }
 
 /// <inheritdoc />
@@ -71,6 +81,18 @@ public record HitData : IHitData
 
     /// <inheritdoc />
     public void Fail() => HasFailed = true;
+
+    private HashSet<StringKey>? _flags;
+
+    /// <inheritdoc />
+    public void SetFlag(StringKey flag)
+    {
+        _flags ??= [];
+        _flags.Add(flag);
+    }
+
+    /// <inheritdoc />
+    public bool HasFlag(StringKey flag) => _flags != null && _flags.Contains(flag);
 }
 
 /// <summary>