Mining Points Carryover (#22941)

* Mining points now carry over between rounds for each character.
* Mining point carryover is capped at 15,000 points and expires after
one week of inactivity.


AI usage disclosure: The code for this was created in-part using GPT 5.6
Sol.

code/modules/mining/machine_processing.dm

@@ -189,7 +189,7 @@
 		if(ID)
 			if(params["choice"] == "claim")
 				if(points >= 0)
-					ID.mining_points += points
+					ID.adjust_mining_points(points)
 					if(points != 0)
 						ping("<b>\The [src]</b> pings, \"Point transfer complete! Transaction total: [points] points!\"")
 						var/character_id = astype(ID.mob_id.resolve(), /mob/living/carbon/human/)?.character_id