Fix shutdown hangs, bank bag icons/drag-drop, loading screen progress, and login spawn

- Fix shutdown hang: skip vmaDestroyAllocator (walked thousands of allocations),
  replace unsafe pthread_timedjoin_np with plain join + early-exit checks in workers
- Bank window: full icon rendering, click-and-hold pickup (0.10s), drag-drop for
  all bank slots including bank bag equip slots, same-slot drop detection
- Loading screen: process one tile per frame for live progress updates
- Camera reset: trust server position in online mode to avoid spawning under WMOs
- Fix PLAYER_BYTES/PLAYER_BYTES_2 field indices, preserve purchasedBankBagSlots
  across inventory rebuilds, fix bank slot purchase result codes

src/game/inventory.cpp

@@ -105,6 +105,13 @@ bool Inventory::setBankBagSlot(int bagIndex, int slotIndex, const ItemDef& item)
     return true;
 }
 
+bool Inventory::clearBankBagSlot(int bagIndex, int slotIndex) {
+    if (bagIndex < 0 || bagIndex >= BANK_BAG_SLOTS) return false;
+    if (slotIndex < 0 || slotIndex >= bankBags_[bagIndex].size) return false;
+    bankBags_[bagIndex].slots[slotIndex].item = ItemDef{};
+    return true;
+}
+
 int Inventory::getBankBagSize(int bagIndex) const {
     if (bagIndex < 0 || bagIndex >= BANK_BAG_SLOTS) return 0;
     return bankBags_[bagIndex].size;
@@ -115,6 +122,17 @@ void Inventory::setBankBagSize(int bagIndex, int size) {
     bankBags_[bagIndex].size = std::min(size, MAX_BAG_SIZE);
 }
 
+const ItemSlot& Inventory::getBankBagItem(int bagIndex) const {
+    static const ItemSlot EMPTY_SLOT;
+    if (bagIndex < 0 || bagIndex >= BANK_BAG_SLOTS) return EMPTY_SLOT;
+    return bankBags_[bagIndex].bagItem;
+}
+
+void Inventory::setBankBagItem(int bagIndex, const ItemDef& item) {
+    if (bagIndex < 0 || bagIndex >= BANK_BAG_SLOTS) return;
+    bankBags_[bagIndex].bagItem.item = item;
+}
+
 void Inventory::swapBagContents(int bagA, int bagB) {
     if (bagA < 0 || bagA >= NUM_BAG_SLOTS || bagB < 0 || bagB >= NUM_BAG_SLOTS) return;
     if (bagA == bagB) return;