fix(admin): align UTM notes and block obsolete chb publication

admin/src/Transport.php

@@ -78,6 +78,7 @@ final class Transport
     public function test(): array {return $this->call(['op'=>'test']);}
     public function readConfig(): array {$r=$this->call(['op'=>'read']);return ['config'=>Config::decode($r['content']),'version'=>$r['version'],'content'=>$r['content']];}
     public function writeConfig(string $version,string $content): array {
+        Config::assertWritable(Config::decode($content));
         $before=$this->call(['op'=>'read']);if(!hash_equals($version,$before['version']))throw new Conflict();
         $this->store->backup($this->target['id'],$before['content']);
         return $this->call(['op'=>'write','version'=>$version,'content'=>$content]);