Send only recipe notification changes on inventory download

Lua includes its current cleared recipe list in the download request. The instance plugin diffs it against the stored list and sends back the names to add and remove instead of the full list. Lua rebuilds the full list from the snapshot kept in the download record and runs the existing deserializer, so the end state is unchanged.

Also stop the serializer from appending to the stored failed recipe list in place, which grew the list on every upload without a download in between.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

plugins/inventory_sync/module/inventory_sync.lua

@@ -111,6 +111,13 @@ function inventory_sync.deserialize_player(player, finished_record)
 	-- Deserialize downloaded player data
 	local serialized_player = compat.json_to_table(finished_record.data)
 	assert(type(serialized_player) == "table", "wrong type for serialized_player")
+	if serialized_player.recipe_notifications_delta then
+		serialized_player.recipe_notifications = serialize.apply_crafting_notification_delta(
+			assert(finished_record.recipe_notifications, "recipe notification delta without snapshot"),
+			serialized_player.recipe_notifications_delta
+		)
+		serialized_player.recipe_notifications_delta = nil
+	end
 	script_data.failed_deserialization[player.name] = serialize.deserialize_player(player, serialized_player)
 
 	-- Restore player position and driving state
@@ -441,8 +448,14 @@ function inventory_sync.initiate_inventory_download(player, player_record, gener
 	local script_data = get_script_data()
 	script_data.active_downloads[player.name] = record
 
+	-- The plugin only sends back what differs from the current notification state
+	record.recipe_notifications = serialize.crafting_notification_snapshot(
+		player, script_data.failed_deserialization[player.name]
+	)
+
 	clusterio_api.send_json("inventory_sync_download", {
-		player_name = player.name
+		player_name = player.name,
+		recipe_notifications = record.recipe_notifications,
 	})
 
 	-- If this is a synced player turn them into a spectator while the