Gradient descent training + Added all dataset + graphs improvements

resources/js/pages/PerceptronViewer.vue

@@ -155,6 +155,8 @@ function getActivationFunction(type: string): (x: number) => number {
             return (x) => 1 / (1 + Math.exp(-x));
         case 'tanh':
             return (x) => Math.tanh(x);
+        case 'linear':
+            return (x) => x;
         default:
             return (x) => x; // Identity function as fallback
     }