feat(ui): unify resource headings with responsive action menus

Add responsive overflow handling and dedicated action menus for application,
service, database, and server headings, while improving upgrade and email
settings flows and returning 404s for missing deployment environments.

routes/web.php

@@ -118,8 +118,12 @@ Route::middleware(['throttle:login'])->group(function () {
 Route::get('/auth/{provider}/redirect', [OauthController::class, 'redirect'])->name('auth.redirect');
 Route::get('/auth/{provider}/callback', [OauthController::class, 'callback'])->name('auth.callback');
 
-// Local-only previews for redesigned HTTP error pages (never registered in production).
-if (app()->environment('local')) {
+// Local/testing previews for HTTP error pages and the Laravel debug renderer (never in production).
+if (app()->environment(['local', 'testing'])) {
+    Route::get('/__exception', function () {
+        throw new RuntimeException('Testing Laravel exception page');
+    })->name('dev.exception-preview');
+
     Route::get('/__error/{code}', function (string $code) {
         $allowed = ['400', '401', '402', '403', '404', '419', '429', '500', '503'];
         abort_unless(in_array($code, $allowed, true), 404);