[Bug Fix] Enhance SummonItemIntoInventory() to support stacking of items (#5022)

* Initial plan

* Initial plan

* Enhance SummonItemIntoInventory to support stacking

Co-authored-by: Valorith <76063792+Valorith@users.noreply.github.com>

* Update .gitignore

* Revert "Update .gitignore"

This reverts commit 16159398d8.

* Disable PCH for patch sources compiled with -O0

Disables precompiled headers for specific patch source files that are compiled with -O0 on UNIX. This avoids Clang errors caused by __OPTIMIZE__ macro state mismatches between the PCH and translation units.

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>

zone/inventory.cpp

@@ -4607,26 +4607,32 @@ void Client::SummonItemIntoInventory(
 		return;
 	}
 
-	const bool  is_arrow = inst->GetItem()->ItemType == EQ::item::ItemTypeArrow;
-	const int16 slot_id  = m_inv.FindFreeSlot(
-		inst->IsClassBag(),
-		true,
-		inst->GetItem()->Size,
-		is_arrow
-	);
+	// Try stacking first if the item is stackable, then fall back to finding a free slot
+	if (!PutItemInInventoryWithStacking(inst)) {
+		// PutItemInInventoryWithStacking failed, fall back to original behavior
+		const bool  is_arrow = inst->GetItem()->ItemType == EQ::item::ItemTypeArrow;
+		const int16 slot_id  = m_inv.FindFreeSlot(
+			inst->IsClassBag(),
+			true,
+			inst->GetItem()->Size,
+			is_arrow
+		);
 
-	SummonItem(
-		item_id,
-		charges,
-		aug1,
-		aug2,
-		aug3,
-		aug4,
-		aug5,
-		aug6,
-		is_attuned,
-		slot_id
-	);
+		SummonItem(
+			item_id,
+			charges,
+			aug1,
+			aug2,
+			aug3,
+			aug4,
+			aug5,
+			aug6,
+			is_attuned,
+			slot_id
+		);
+	}
+
+	safe_delete(inst);
 }
 
 bool Client::HasItemOnCorpse(uint32 item_id)