Update pihole module

modules/pihole/pages/api.php

@@ -97,10 +97,26 @@ $apiRequest = function (array $instance, array $params) use ($normalizeApiPath):
     return ['ok' => true, 'data' => $data, 'http_code' => $httpCode, 'url' => $full];
 };
 
-$pickInstances = function (string $target) use ($instances): array {
+$resolvePrimaryId = function () use ($instances): ?string {
+    foreach ($instances as $id => $row) {
+        if (!empty($row['is_primary'])) {
+            return $id;
+        }
+    }
+    $first = array_key_first($instances);
+    return $first !== null ? (string)$first : null;
+};
+
+$pickInstances = function (string $target) use ($instances, $resolvePrimaryId): array {
     if ($target === 'all') {
         return $instances;
     }
+    if ($target === 'primary') {
+        $primaryId = $resolvePrimaryId();
+        if ($primaryId !== null && isset($instances[$primaryId])) {
+            return [$primaryId => $instances[$primaryId]];
+        }
+    }
     if (isset($instances[$target])) {
         return [$target => $instances[$target]];
     }