feat(Core/Player): Implement ACCOUNT_FLAG_TRIAL (#26064)

Co-authored-by: Ludwig <sudlud@users.noreply.github.com>
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

src/server/game/Handlers/GuildHandler.cpp

@@ -21,6 +21,7 @@
 #include "Log.h"
 #include "ObjectMgr.h"
 #include "SocialMgr.h"
+#include "World.h"
 #include "WorldSession.h"
 
 void WorldSession::HandleGuildQueryOpcode(WorldPackets::Guild::QueryGuildInfo& query)
@@ -59,6 +60,14 @@ void WorldSession::HandleGuildAcceptOpcode(WorldPackets::Guild::AcceptGuildInvit
 {
     LOG_DEBUG("guild", "CMSG_GUILD_ACCEPT [{}]", GetPlayer()->GetName());
 
+    if (sWorld->getBoolConfig(CONFIG_TRIAL_RESTRICTION_GUILD) && IsTrialAccount())
+    {
+        Guild::SendCommandResult(this, GUILD_COMMAND_INVITE, ERR_GUILD_PERMISSIONS);
+        GetPlayer()->SetGuildIdInvited(0);
+        GetPlayer()->SetInGuild(0);
+        return;
+    }
+
     if (!GetPlayer()->GetGuildId())
         if (Guild* guild = sGuildMgr->GetGuildById(GetPlayer()->GetGuildIdInvited()))
             guild->HandleAcceptMember(this);