Refactor Administration entrypoint

We moved the administration item to the company switcher in the header

app/Http/Controllers/Admin/AdminDashboardController.php

@@ -0,0 +1,48 @@
+<?php
+
+namespace App\Http\Controllers\Admin;
+
+use App\Http\Controllers\Controller;
+use App\Models\Company;
+use App\Models\User;
+use Illuminate\Http\JsonResponse;
+use Illuminate\Support\Facades\DB;
+use Illuminate\Support\Facades\File;
+
+class AdminDashboardController extends Controller
+{
+    public function index(): JsonResponse
+    {
+        $version = preg_replace('~[\r\n]+~', '', File::get(base_path('version.md')));
+
+        $dbDriver = config('database.default');
+        $dbVersion = $this->getDatabaseVersion($dbDriver);
+
+        return response()->json([
+            'app_version' => $version,
+            'php_version' => phpversion(),
+            'database' => [
+                'driver' => $dbDriver,
+                'version' => $dbVersion,
+            ],
+            'counts' => [
+                'companies' => Company::count(),
+                'users' => User::count(),
+            ],
+        ]);
+    }
+
+    private function getDatabaseVersion(string $driver): ?string
+    {
+        try {
+            return match ($driver) {
+                'mysql' => DB::selectOne('SELECT VERSION() as version')?->version,
+                'pgsql' => DB::selectOne('SHOW server_version')?->server_version,
+                'sqlite' => DB::selectOne('SELECT sqlite_version() as version')?->version,
+                default => null,
+            };
+        } catch (\Throwable) {
+            return null;
+        }
+    }
+}