feat(operations): fresh platform-operations implementation

Full rewrite of the installer (incl. the finish step), self-update pipeline,
settings store, cron webhook, dashboard/bootstrap surface, environment
manager, wizard login, config endpoint and shared helpers. Byte-compatible
public interfaces and observable behavior, including documented legacy
quirks; verified by the pilot behavioral suite and the full test suite.

app/Platform/Operations/Http/Webhooks/CronJobController.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace App\Platform\Operations\Http\Webhooks;
+
+use App\Platform\Http\Controller;
+use Illuminate\Http\JsonResponse;
+use Illuminate\Http\Request;
+use Illuminate\Support\Facades\Artisan;
+
+/**
+ * Webhook that lets an external scheduler drive Laravel's own scheduler on
+ * installs that cannot register a system cron entry.
+ */
+class CronJobController extends Controller
+{
+    /**
+     * Run the due scheduled tasks. The shared-token check has already been
+     * made by the route middleware, so nothing is read off the request.
+     */
+    public function __invoke(Request $request): JsonResponse
+    {
+        Artisan::call('schedule:run');
+
+        return response()->json(['success' => true]);
+    }
+}