Initial Kaffeekasse SaaS restart

app/Core/TenantContext.php

@@ -0,0 +1,23 @@
+<?php
+
+namespace App\Core;
+
+use PDO;
+
+final class TenantContext
+{
+    public function __construct(private readonly PDO $pdo)
+    {
+    }
+
+    public function bySlug(string $slug): ?array
+    {
+        $statement = $this->pdo->prepare(
+            'SELECT * FROM tenants WHERE slug = :slug LIMIT 1'
+        );
+        $statement->execute(['slug' => $slug]);
+        $tenant = $statement->fetch();
+
+        return $tenant ?: null;
+    }
+}