Fix issues discovered via TypeMaker (#87596)

## About The Pull Request
Fixes issues with var typing and proc arguments, discovered using
OpenDream's WIP TypeMaker feature (using improvements I haven't PR'd
upstream yet).

## Why It's Good For The Game
Codebase maintenance.

code/modules/research/techweb/_techweb_node.dm

@@ -34,7 +34,7 @@
 	var/category = "Misc"
 	/// The list of experiments required to research the node
 	var/list/required_experiments = list()
-	/// If completed, these experiments give a specific point amount discount to the node.area
+	/// If completed, these experiments give a specific point amount discount to the node.
 	var/list/discount_experiments = list()
 	/// When this node is completed, allows these experiments to be performed.
 	var/list/experiments_to_unlock = list()