Add comprehensive test coverage and update notes

tests/Unit/ResetUserPasswordTest.php

@@ -0,0 +1,20 @@
+<?php
+
+use App\Actions\Fortify\ResetUserPassword;
+use App\Models\User;
+use Illuminate\Support\Facades\Hash;
+
+it('resets user password after validation', function (): void {
+    $user = User::factory()->create([
+        'password' => Hash::make('OldPass123!'),
+    ]);
+
+    $action = new ResetUserPassword();
+    $action->reset($user, [
+        'password' => 'NewPass123!',
+        'password_confirmation' => 'NewPass123!',
+    ]);
+
+    $user->refresh();
+    expect(Hash::check('NewPass123!', $user->password))->toBeTrue();
+});