feat(deployments): track application configuration diffs

Store deployment configuration snapshots on application deployment queues and compare them against the current application state. Surface grouped pending changes in the configuration checker and use build-impact diffs to decide when an existing image can skip the build step.

tests/Feature/ApplicationGeneralBuildpackSelectorTest.php

@@ -67,7 +67,7 @@ test('existing application buildpack selector lists nixpacks before railpack', f
         ], false);
 });
 
-test('existing application shows railpack beta badge in build helper copy', function () {
+test('existing application shows railpack beta label in build pack selector', function () {
     $application = Application::factory()->create([
         'environment_id' => $this->environment->id,
         'destination_id' => $this->destination->id,
@@ -81,6 +81,5 @@ test('existing application shows railpack beta badge in build helper copy', func
 
     Livewire::test(General::class, ['application' => $application])
         ->assertSuccessful()
-        ->assertSee('Railpack')
-        ->assertSee('Beta');
+        ->assertSee('Railpack (Beta)');
 });