Add attribute system with core stats and gameplay components

GameCore/Math/Vector3.cs

@@ -0,0 +1,79 @@
+namespace GameCore.Math;
+
+/// <summary>
+///     A simple, engine-agnostic 3D vector struct.
+///     We use our own to avoid dependencies on Godot or Unity's vector types
+///     within the GameCore library, ensuring it remains portable.
+/// </summary>
+public struct Vector3
+{
+    public float X;
+    public float Y;
+    public float Z;
+
+    public static readonly Vector3 Zero = new(0, 0, 0);
+
+    public Vector3(float x, float y, float z)
+    {
+        X = x;
+        Y = y;
+        Z = z;
+    }
+
+    public static Vector3 operator +(Vector3 a, Vector3 b)
+    {
+        return new Vector3(a.X + b.X, a.Y + b.Y, a.Z + b.Z);
+    }
+
+    public static Vector3 operator -(Vector3 a, Vector3 b)
+    {
+        return new Vector3(a.X - b.X, a.Y - b.Y, a.Z - b.Z);
+    }
+
+    public static Vector3 operator *(Vector3 a, float d)
+    {
+        return new Vector3(a.X * d, a.Y * d, a.Z * d);
+    }
+
+    public override string ToString()
+    {
+        return $"({X}, {Y}, {Z})";
+    }
+
+    public override bool Equals(object obj)
+    {
+        if (obj is not Vector3 other)
+            return false;
+
+        return X == other.X && Y == other.Y && Z == other.Z;
+    }
+
+    public override int GetHashCode()
+    {
+        return HashCode.Combine(X, Y, Z);
+    }
+
+    public static bool operator ==(Vector3 a, Vector3 b)
+    {
+        return a.Equals(b);
+    }
+
+    public static bool operator !=(Vector3 a, Vector3 b)
+    {
+        return !a.Equals(b);
+    }
+
+    public float Length()
+    {
+        return (float)System.Math.Sqrt(X * X + Y * Y + Z * Z);
+    }
+
+    public Vector3 Normalize()
+    {
+        var length = Length();
+        if (length == 0)
+            return Zero;
+
+        return new Vector3(X / length, Y / length, Z / length);
+    }
+}