fix(vultr): validate public network and token scope

Require IPv6 when public IPv4 is disabled, constrain cloud token
lookup by team and provider during deletion, and encode Vultr instance IDs
in API paths.

tests/Feature/VultrServerCreationTest.php

@@ -133,3 +133,18 @@ it('creates a Vultr server through the Livewire flow', function () {
             && $request['user_data'] === base64_encode("#cloud-config\npackages:\n  - curl");
     });
 });
+
+it('requires IPv6 when public IPv4 is disabled', function () {
+    Livewire::test(ByVultr::class)
+        ->set('selected_token_id', $this->vultrToken->id)
+        ->set('current_step', 2)
+        ->set('server_name', 'test-vultr-server')
+        ->set('selected_region', 'ewr')
+        ->set('selected_plan', 'vc2-1c-1gb')
+        ->set('selected_os_id', 2284)
+        ->set('private_key_id', $this->privateKey->id)
+        ->set('enable_ipv6', false)
+        ->set('disable_public_ipv4', true)
+        ->call('submit')
+        ->assertHasErrors(['enable_ipv6']);
+});