Partnership: handle empty run.php response gracefully

If run.php returns an empty body (transient nginx/PHP-FPM issue), the script
still runs via nohup. Treat empty response as ok instead of throwing a
JSON parse error that misleads the user into thinking the action failed.

Plugin/unraid/pages/partnership.php

@@ -63,7 +63,17 @@ function _vvPtRun(id, extraArgs) {
   return fetch('/plugins/varaverk/api/run.php', {
     method: 'POST',
     body: new URLSearchParams(params)
-  }).then(r => r.json());
+  }).then(r => {
+    if (!r.ok) throw new Error('HTTP ' + r.status);
+    return r.text();
+  }).then(text => {
+    if (!text.trim()) {
+      // Empty body — script likely started via nohup before response was sent.
+      // Treat as ok; check Scheduler log for confirmation.
+      return {ok: true, _empty_response: true};
+    }
+    return JSON.parse(text);
+  });
 }
 
 function vvPtPhase1(btn, hostId) {