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)

config/app.php

@@ -172,7 +172,7 @@ return [
 //        App\Providers\Filament\DashboardPanelProvider::class,
         App\Providers\RouteServiceProvider::class,
         \App\Providers\ForceHttpsServiceProvider::class,
-        // \App\Containers\VikonIntegration\Providers\VikonServiceProvider::class, // will be re-added
+        \App\Containers\VikonIntegration\Providers\VikonServiceProvider::class,
     ])->toArray(),
 
     /*