Resolve Custom script ids where the scripts actually live

The Custom/ prefix is a namespace, not a directory under SCRIPTS_DIR, so every
launcher that resolved it as one could never find the script.

Plugin/unraid/api/run.php

@@ -77,7 +77,10 @@ if (!$id || !preg_match('/^[a-zA-Z0-9_.\/\-]+\.sh$/', $id) || str_contains($id,
     exit;
 }
 
-$script = SCRIPTS_DIR . '/' . $id;
+// Custom scripts live outside the repo (CUSTOM_SCRIPTS_DIR) — everything else resolves under SCRIPTS_DIR.
+$script = str_starts_with($id, 'Custom/')
+    ? CUSTOM_SCRIPTS_DIR . '/' . substr($id, strlen('Custom/'))
+    : SCRIPTS_DIR . '/' . $id;
 if (!file_exists($script)) {
     echo json_encode(['ok' => false, 'error' => 'Script not found: ' . $id]);
     exit;