fix: send GAMEOBJ_USE+LOOT together for chests, reset off-screen bag pos

Chest-type GOs now send CMSG_GAMEOBJ_USE immediately followed by
CMSG_LOOT in the same frame. The USE handler opens the chest, then the
LOOT handler reads the contents — both processed sequentially by the
server. Previously only CMSG_LOOT was sent (no USE), which failed on
AzerothCore because the chest wasn't activated first.

Reset the Bags window position to bottom-right if the saved position
is outside the current screen resolution (e.g. after a resolution
change or moving between monitors).

src/game/game_handler.cpp

@@ -21335,12 +21335,12 @@ void GameHandler::performGameObjectInteractionNow(uint64_t guid) {
              " name='", goName, "' chestLike=", chestLike, " isMailbox=", isMailbox);
 
     if (chestLike) {
-        // For chest-like GOs (quest objects, treasure chests, etc.), send CMSG_LOOT
-        // directly with the GO GUID — same as creature corpse looting. The server's
-        // LOOT handler activates the GO, generates loot, and sends SMSG_LOOT_RESPONSE
-        // in a single step. Sending CMSG_GAMEOBJ_USE + delayed CMSG_LOOT doesn't work
-        // because the USE handler opens+despawns the GO before CMSG_LOOT arrives, and
-        // CMSG_LOOT's DoLootRelease() closes any loot the USE handler already opened.
+        // For chest-like GOs: send CMSG_GAMEOBJ_USE (opens the chest) followed
+        // immediately by CMSG_LOOT (requests loot contents). Both sent in the
+        // same frame so the server processes them sequentially: USE transitions
+        // the GO to lootable state, then LOOT reads the contents.
+        auto usePacket = GameObjectUsePacket::build(guid);
+        socket->send(usePacket);
         lootTarget(guid);
         lastInteractedGoGuid_ = guid;
     } else {

src/ui/inventory_screen.cpp

@@ -941,6 +941,14 @@ void InventoryScreen::renderAggregateBags(game::Inventory& inventory, uint64_t m
         return;
     }
 
+    // Reset to bottom-right if the window ended up outside the screen (resolution change)
+    ImVec2 winPos = ImGui::GetWindowPos();
+    ImVec2 winSize = ImGui::GetWindowSize();
+    if (winPos.x > screenW || winPos.y > screenH ||
+        winPos.x + winSize.x < 0 || winPos.y + winSize.y < 0) {
+        ImGui::SetWindowPos(ImVec2(posX, posY));
+    }
+
     renderBackpackPanel(inventory, compactBags_);
 
     ImGui::Spacing();