PCD269: define EP_HELPER_USER and EP_HELPER_PASS from env (stage 2)

Mirrors the existing ELASTICSEARCH_DOCS_HOST → EP_HELPER_HOST pattern
so that when ELASTICSEARCH_DOCS_USER and ELASTICSEARCH_DOCS_PASS are
set in the pod env, the wp-proud-search-elastic plugin will send
Authorization: Basic on docsapi calls.

Env vars are intentionally not provisioned yet — the constants stay
undefined and the plugin behaves exactly as before. Stage 3 will add
the k8s Secret and wire the env vars per pod, then stage 4 flips
routeAuth on the docsapi side.

Refs PCD269.

Author: curtismchale

www/wp-config.php

@@ -103,6 +103,12 @@
 if (getenv('ELASTICSEARCH_DOCS_HOST')) {
     define('EP_HELPER_HOST', 'http://' . getenv('ELASTICSEARCH_DOCS_HOST') . '/send-attachments');
 }
+if (getenv('ELASTICSEARCH_DOCS_USER')) {
+    define('EP_HELPER_USER', getenv('ELASTICSEARCH_DOCS_USER'));
+}
+if (getenv('ELASTICSEARCH_DOCS_PASS')) {
+    define('EP_HELPER_PASS', getenv('ELASTICSEARCH_DOCS_PASS'));
+}
 
 define('DISALLOW_FILE_EDIT', true);
 define('DISALLOW_FILE_MODS', true);