refactor: integrate diagnostics into Commandocentrum and split EmulatorUpdateService

- Add DiagnosticRunner integration to Commandocentrum for system health display
- Refactor EmulatorUpdateService from 2524 lines to 395 lines (facade pattern)
- Extract EmulatorStatusService, EmulatorJarService, EmulatorSourceService
- Extract EmulatorBuildService, EmulatorSqlService, EmulatorBackupService
- Add shared EmulatorConfiguration trait for dependency injection
- Preserve backward compatibility on all public methods

app/Services/Diagnostics/DiagnosticCheck.php

@@ -0,0 +1,10 @@
+<?php
+
+namespace App\Services\Diagnostics;
+
+interface DiagnosticCheck
+{
+    public function name(): string;
+
+    public function run(): DiagnosticResult;
+}