fix: detection of flash backup activation state (#1769)

Resolves #1767 


plugin/source/dynamix.unraid.net/usr/local/emhttp/plugins/dynamix.my.servers/include/UpdateFlashBackup.php:415
still reads the API version from _var($mystatus,'version'), but commit
441e180 removed the code that populates $mystatus (the parse of
/var/local/emhttp/myservers.cfg). As a result $mystatus is undefined, so
we now send api_version= to the flash activation endpoint. The PHP
runtime also emits “Undefined variable: mystatus” / “Trying to access
array offset on value of type null” notices before headers are written.
Those notices corrupt the JSON response, the keyserver rejects the
request because the api_version is missing, and the flash backup state
file is never updated—so the web GUI stays stuck at “Loading”.

Because the status request always invokes UpdateFlashBackup.php, every
page load trips the same failure path, leaving
/var/local/emhttp/flashbackup.ini with loading=Loading. The frontend
only listens for /sub/flashbackup events, so until that INI file is
rewritten the spinner never clears and the enable button never becomes
active.

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* UI now initializes flash backup status on page load so backup controls
reflect current server state immediately.
* Backup state saves now publish remote updates, improving
synchronization of backup status.

* **Bug Fixes**
* Improved API version handling for flash backup operations: sends
version when available and falls back gracefully when unknown.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: pujitm

plugin/source/dynamix.unraid.net/usr/local/emhttp/plugins/dynamix.my.servers/Connect.page

@@ -575,12 +575,30 @@ _(Flash backup)_:
 <script>
 changeRemoteAccess($('#remoteAccess'));
 var flashbackupsub = new NchanSubscriber('/sub/flashbackup');
+var initialFlashBackupState = <?=
+    json_encode(
+        $flashbackup_status ?: [],
+        JSON_HEX_TAG | JSON_HEX_APOS | JSON_HEX_QUOT | JSON_HEX_AMP
+    )
+?> || {};
+
+if (Object.keys(initialFlashBackupState).length === 0) {
+  initialFlashBackupState = {
+    activated: 'no',
+    uptodate: 'no',
+    loading: '',
+    error: '',
+    remoteerror: ''
+  };
+}
+
 flashbackupsub.on('message', function(data) {
   var ini = parseINI(data);
 
   buttonStateReset(ini['flashbackup']);
 });
 $(function() {
+  buttonStateReset(initialFlashBackupState);
   flashbackupsub.start();
   if ( typeof caPluginUpdateCheck === "function" ) {
     caPluginUpdateCheck("dynamix.unraid.net.plg",{name:"Unraid Connect"});
@@ -602,4 +620,3 @@ _(OIDC Configuration)_:
 
 <!-- start unraid-api section -->
 <unraid-connect-settings></unraid-connect-settings>
-

plugin/source/dynamix.unraid.net/usr/local/emhttp/plugins/dynamix.my.servers/include/UpdateFlashBackup.php

@@ -18,6 +18,7 @@
 
 $docroot ??= ($_SERVER['DOCUMENT_ROOT'] ?: '/usr/local/emhttp');
 require_once "$docroot/webGui/include/Wrappers.php";
+require_once "$docroot/webGui/include/publish.php";
 require_once "$docroot/plugins/dynamix.my.servers/include/connect-config.php";
 
 $isRegistered = ConnectConfig::isUserSignedIn();
@@ -32,6 +33,7 @@
 }
 
 $isConnected = ($connectionStatus === 'CONNECTED') ? true : false;
+$apiVersion = ApiConfig::getApiVersion();
 
 $flashbackup_ini = '/var/local/emhttp/flashbackup.ini';
 
@@ -75,6 +77,7 @@ function save_flash_backup_state($loading='') {
   $flashbackup_tmp = '/var/local/emhttp/flashbackup.new';
   file_put_contents($flashbackup_tmp, $text);
   rename($flashbackup_tmp, $flashbackup_ini);
+  publish('flashbackup', $text);
 }
 
 function default_flash_backup_state() {
@@ -416,7 +419,7 @@ function deleteLocalRepo() {
 curl_setopt($ch, CURLOPT_POSTFIELDS, [
   'keyfile' => $keyfile,
   'version' => _var($var,'version'),
-  'api_version' => _var($mystatus, 'version'),
+  'api_version' => ($apiVersion && $apiVersion !== 'unknown') ? $apiVersion : '',
   'bzfiles' => implode(',', $bzfilehashes)
 ]);
 curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);