Add thread safety for group operations (#1816)

Fixes crashes and race conditions when bots perform group/guild/arena
operations by moving thread-unsafe code to world thread.

Potentially fixes #1124

## Changes

- Added operation queue system that runs in world thread
- Group operations (invite, remove, convert to raid, set leader) now
queued
- Arena formation refactored to use queue
- Guild operations changed to use packet queueing

## Testing

Set `MapUpdate.Threads` > 1 in worldserver.conf to enable multiple map
threads, then test:
- Group formation and disbanding
- Arena team formation
- Guild operations (invite, promote, demote, remove)

- Run with TSAN
cmake ../ \
  -DCMAKE_CXX_FLAGS="-fsanitize=thread -g -O1" \
  -DCMAKE_C_FLAGS="-fsanitize=thread -g -O1" \
  -DCMAKE_EXE_LINKER_FLAGS="-fsanitize=thread" \
  -DCMAKE_INSTALL_PREFIX=/path/to/install \
  -DCMAKE_BUILD_TYPE=RelWithDebInfo

build

export
TSAN_OPTIONS="log_path=tsan_report:halt_on_error=0:second_deadlock_stack=1"
./worldserver

The crashes/race conditions should no longer occur with concurrent map
threads.

## New Files

- `PlayerbotOperation.h` - Base class defining the operation interface
(Execute, IsValid, GetPriority)
- `PlayerbotOperations.h` - Concrete implementations:
GroupInviteOperation, GroupRemoveMemberOperation,
GroupConvertToRaidOperation, GroupSetLeaderOperation,
ArenaGroupFormationOperation
- `PlayerbotWorldThreadProcessor.h/cpp` - Singleton processor with
mutex-protected queue, processes operations in WorldScript::OnUpdate
hook, handles batch processing and validation

---------

Co-authored-by: blinkysc <blinkysc@users.noreply.github.com>
Co-authored-by: SaW <swerkhoven@outlook.com>
Co-authored-by: bash <hermensb@gmail.com>

src/PlayerbotMgr.cpp

@@ -27,7 +27,9 @@
 #include "PlayerbotAIConfig.h"
 #include "PlayerbotDbStore.h"
 #include "PlayerbotFactory.h"
+#include "PlayerbotOperations.h"
 #include "PlayerbotSecurity.h"
+#include "PlayerbotWorldThreadProcessor.h"
 #include "Playerbots.h"
 #include "RandomPlayerbotMgr.h"
 #include "SharedDefines.h"
@@ -85,7 +87,6 @@ public:
 
 void PlayerbotHolder::AddPlayerBot(ObjectGuid playerGuid, uint32 masterAccountId)
 {
-    // bot is loading
     if (botLoading.find(playerGuid) != botLoading.end())
         return;
 
@@ -195,7 +196,9 @@ void PlayerbotHolder::HandlePlayerBotLoginCallback(PlayerbotLoginQueryHolder con
     }
 
     sRandomPlayerbotMgr->OnPlayerLogin(bot);
-    OnBotLogin(bot);
+
+    auto op = std::make_unique<OnBotLoginOperation>(bot->GetGUID(), this);
+    sPlayerbotWorldProcessor->QueueOperation(std::move(op));
 
     botLoading.erase(holder.GetGuid());
 }
@@ -316,11 +319,9 @@ void PlayerbotHolder::LogoutPlayerBot(ObjectGuid guid)
         if (!botAI)
             return;
 
-        Group* group = bot->GetGroup();
-        if (group && !bot->InBattleground() && !bot->InBattlegroundQueue() && botAI->HasActivePlayerMaster())
-        {
-            sPlayerbotDbStore->Save(botAI);
-        }
+        // Queue group cleanup operation for world thread
+        auto cleanupOp = std::make_unique<BotLogoutGroupCleanupOperation>(guid);
+        sPlayerbotWorldProcessor->QueueOperation(std::move(cleanupOp));
 
         LOG_DEBUG("playerbots", "Bot {} logging out", bot->GetName().c_str());
         bot->SaveToDB(false, false);
@@ -549,6 +550,7 @@ void PlayerbotHolder::OnBotLogin(Player* const bot)
 
     botAI->TellMaster("Hello!", PLAYERBOT_SECURITY_TALK);
 
+    // Queue group operations for world thread
     if (master && master->GetGroup() && !group)
     {
         Group* mgroup = master->GetGroup();
@@ -556,24 +558,29 @@ void PlayerbotHolder::OnBotLogin(Player* const bot)
         {
             if (!mgroup->isRaidGroup() && !mgroup->isLFGGroup() && !mgroup->isBGGroup() && !mgroup->isBFGroup())
             {
-                mgroup->ConvertToRaid();
+                // Queue ConvertToRaid operation
+                auto convertOp = std::make_unique<GroupConvertToRaidOperation>(master->GetGUID());
+                sPlayerbotWorldProcessor->QueueOperation(std::move(convertOp));
             }
             if (mgroup->isRaidGroup())
             {
-                mgroup->AddMember(bot);
+                // Queue AddMember operation
+                auto addOp = std::make_unique<GroupInviteOperation>(master->GetGUID(), bot->GetGUID());
+                sPlayerbotWorldProcessor->QueueOperation(std::move(addOp));
             }
         }
         else
         {
-            mgroup->AddMember(bot);
+            // Queue AddMember operation
+            auto addOp = std::make_unique<GroupInviteOperation>(master->GetGUID(), bot->GetGUID());
+            sPlayerbotWorldProcessor->QueueOperation(std::move(addOp));
         }
     }
     else if (master && !group)
     {
-        Group* newGroup = new Group();
-        newGroup->Create(master);
-        sGroupMgr->AddGroup(newGroup);
-        newGroup->AddMember(bot);
+        // Queue group creation and AddMember operation
+        auto inviteOp = std::make_unique<GroupInviteOperation>(master->GetGUID(), bot->GetGUID());
+        sPlayerbotWorldProcessor->QueueOperation(std::move(inviteOp));
     }
     // if (master)
     // {