feat(vikon): rewrite VikonIntegration from scratch — OAuth + core update

- HttpTask: Laravel Http facade with SSL enabled, retry, timeout
- ValidateTokenTask: token check via auth.db-nica.ru
- RefreshTokenTask: token refresh via db-nica.ru
- FilesystemTask: path traversal protection, blocked extensions (PHP/ASP/etc)
- AuthenticateAction: OAuth2 code→token exchange
- CheckAccessAction: token validation + filesystem writability check
- CheckVersionAction: version comparison against remote API
- UpdateCoreAction: ZIP download, Zip Slip protection, atomic sync with rollback
- VikonController: thin controller, 7 endpoints with Session-based token storage
- Routes: access-check, dashboard.auth, throttle:30,1 middleware
- Vue 3 Composition API frontend with progress bar
- Config: all secrets in .env via config/vikon.php
- vikon_core kept as fallback (not deleted)

app/Containers/VikonIntegration/Tasks/ValidateTokenTask.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace App\Containers\VikonIntegration\Tasks;
+
+use Illuminate\Support\Facades\Log;
+
+class ValidateTokenTask
+{
+    public function __construct(
+        private readonly HttpTask $http,
+    ) {}
+
+    public function run(string $accessToken): bool
+    {
+        try {
+            $response = $this->http->getWithToken(
+                'api/profile_applicant/check_access_token',
+                $accessToken,
+                'auth'
+            );
+            return $response->successful();
+        } catch (\Throwable $e) {
+            Log::warning('Vikon token validation failed', ['error' => $e->getMessage()]);
+            return false;
+        }
+    }
+}