fix(applications): ignore missing health on additional server status

Closes #11892

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app/Models/Application.php

@@ -971,11 +971,11 @@ class Application extends BaseModel
                     $additional_servers_status = $this->additional_servers->pluck('pivot.status');
                     foreach ($additional_servers_status as $status) {
                         $server_status = str($status)->before(':')->value();
-                        $server_health = str($status)->after(':')->value() ?? 'unhealthy';
+                        $server_health = str($status)->contains(':') ? str($status)->after(':')->value() : null;
                         if ($main_server_status !== $server_status) {
                             $complex_status = 'degraded';
                         }
-                        if ($main_server_health !== $server_health) {
+                        if ($server_health !== null && $main_server_health !== $server_health) {
                             $complex_health = 'unhealthy';
                         }
                     }

tests/Unit/ApplicationAdditionalServerStatusTest.php

@@ -0,0 +1,28 @@
+<?php
+
+use App\Models\Application;
+
+function applicationWithAdditionalServerStatuses(string $mainStatus, array $additionalStatuses): Application
+{
+    $application = new Application;
+    $application->setRawAttributes(['status' => $mainStatus]);
+    $application->setRelation('additional_servers', collect($additionalStatuses)
+        ->map(fn (string $status) => (object) ['pivot' => (object) ['status' => $status]]));
+
+    return $application;
+}
+
+it('stays healthy when an additional server status has no health segment', function () {
+    expect(applicationWithAdditionalServerStatuses('running:healthy', ['running'])->status)
+        ->toBe('running:healthy');
+});
+
+it('reports unhealthy when an additional server has an explicit unhealthy status', function () {
+    expect(applicationWithAdditionalServerStatuses('running:healthy', ['running:unhealthy'])->status)
+        ->toBe('running:unhealthy');
+});
+
+it('reports degraded when an additional server status without health differs', function () {
+    expect(applicationWithAdditionalServerStatuses('running:healthy', ['exited'])->status)
+        ->toBe('degraded:healthy');
+});