Add __set that throws to fully enforce Location immutability

Without __set, PHP 8.2+ only emits a deprecation for dynamic property
assignment rather than preventing it. Adding an explicit __set that
throws BadMethodCallException closes this gap.

Author: alies-dev

src/Location.php

@@ -185,6 +185,16 @@ public function offsetUnset(mixed $offset): void
         throw new \BadMethodCallException('Location is immutable.');
     }
 
+    /**
+     * Prevent setting properties directly.
+     *
+     * @throws \BadMethodCallException Always, as Location is immutable.
+     */
+    public function __set(string $key, mixed $value): void
+    {
+        throw new \BadMethodCallException('Location is immutable. Use withAttribute() instead.');
+    }
+
     /** Check if the location's attribute is set */
     public function __isset($key): bool
     {

tests/LocationTest.php

@@ -27,6 +27,16 @@ public function with_attribute_returns_new_instance_and_original_is_unchanged():
         $this->assertSame('81.2.69.142', $modified->ip);
     }
 
+    #[Test]
+    public function setting_property_via_magic_set_throws_bad_method_call_exception(): void
+    {
+        $location = new Location(['ip' => '127.0.0.1']);
+
+        $this->expectException(\BadMethodCallException::class);
+
+        $location->ip = '10.0.0.1';
+    }
+
     #[Test]
     public function offset_set_throws_bad_method_call_exception(): void
     {