fix(ui): normalize S3 endpoints and remove duplicate config warnings

Normalize endpoints on blur and submit, link internal-target errors to settings, and target the S3 submit loading state.

tests/Feature/S3StorageCreateErrorLinkTest.php

@@ -0,0 +1,16 @@
+<?php
+
+use App\Livewire\Storage\Create;
+
+it('formats the internal target settings route as a clickable link', function () {
+    $settingsUrl = route('settings.advanced').'#endpoint-section';
+    $exception = new RuntimeException("Private target. Configure allowed internal targets: {$settingsUrl}");
+    $method = new ReflectionMethod(Create::class, 'connectionErrorDescription');
+
+    $description = $method->invoke(new Create, $exception);
+
+    expect($description)
+        ->toContain('href="'.$settingsUrl.'"')
+        ->toContain('Set them here.')
+        ->not->toContain('targets: '.$settingsUrl);
+});