adds more hand keybinds (#25225)

code/modules/mob/living/carbon/carbon_procs.dm

@@ -194,18 +194,11 @@
 	SEND_SIGNAL(src, COMSIG_CARBON_SWAP_HANDS)
 
 
-/mob/living/carbon/activate_hand(selhand) //0 or "r" or "right" for right hand; 1 or "l" or "left" for left hand.
-
-	if(istext(selhand))
-		selhand = lowertext(selhand)
-
-		if(selhand == "right" || selhand == "r")
-			selhand = 0
-		if(selhand == "left" || selhand == "l")
-			selhand = 1
-
+/mob/living/carbon/activate_hand(selhand)
 	if(selhand != hand)
 		swap_hand()
+		return TRUE
+	return FALSE
 
 /mob/living/carbon/proc/help_shake_act(mob/living/carbon/M)
 	if(health < HEALTH_THRESHOLD_CRIT)

code/modules/mob/mob.dm

@@ -918,7 +918,7 @@ GLOBAL_LIST_INIT(slot_equipment_priority, list( \
 	return
 
 /mob/proc/activate_hand(selhand)
-	return
+	return FALSE
 
 /mob/dead/observer/verb/respawn()
 	set name = "Respawn as NPC"

code/modules/mob/mob_vars.dm

@@ -44,7 +44,7 @@
 	var/memory = ""
 	var/notransform = FALSE	//Carbon
 	/// True for left hand active, otherwise for right hand active
-	var/hand = null
+	var/hand = HAND_BOOL_RIGHT
 	var/real_name = null
 	var/flavor_text = ""
 	var/med_record = ""