Makes tendrils less out for blood, cleans up The Thing's code (#96332)

## About The Pull Request

I didn't realize that default aggro range for mobs is 9, so tendrils
would try to attack you with their whips and spikes despite you being
completely out of their range, which looks pretty funny.
I've fixed this by separating out aggro ***grab*** range and aggro
sustain ranges, lowering latter to 5 for tendrils, and adding checks for
target distance for both abilities it has. The Thing also had a similar
behavior but used rather jank code for that (which I don't think even
worked), so I've modified it to use the new system as well.

## Why It's Good For The Game

Stationary mobs probably shouldn't try to attack mobs completely out of
their reach

## Changelog
🆑
fix: Tendrils no longer try to attack you when you're out of their reach
code: Cleaned up The Thing's aggro code
/🆑

code/modules/mob/living/basic/boss/thing/thing_ai.dm

@@ -5,14 +5,15 @@
 		BB_THETHING_ATTACKMODE = TRUE, //Whether we are using our melee abilities right now
 		BB_THETHING_NOAOE = TRUE, // Restricts us to only melee abilities
 		BB_THETHING_LASTAOE = null, // Last AOE ability key executed
-		BB_AGGRO_RANGE = 6, //lets not execute hearers for a 16 tile radius
+		BB_AGGRO_RANGE = 16,
+		BB_AGGRO_GRAB_RANGE = 6,
 	)
 
 	ai_movement = /datum/ai_movement/basic_avoidance // dont need anything better because the arena is a square lol
 	idle_behavior = null
 	planning_subtrees = list(
 		/datum/ai_planning_subtree/escape_captivity,
-		/datum/ai_planning_subtree/simple_find_target/increased_range, //aggros at 6, sees 16 tiles
+		/datum/ai_planning_subtree/simple_find_target,
 		/datum/ai_planning_subtree/thing_boss_aoe,
 		/datum/ai_planning_subtree/thing_boss_melee,
 	)

code/modules/mob/living/basic/lavaland/tendril/tendril_actions.dm

@@ -266,6 +266,8 @@
 	cooldown_time = 10 SECONDS
 	melee_cooldown_time = 0
 	shared_cooldown = NONE
+	/// Range in which we create spikes
+	var/spike_range = 7
 	/// Health threshold at which we reduce the amount of empty spots on the ground
 	var/health_threshold = 0.3
 
@@ -288,7 +290,7 @@
 		if (as_living.health / as_living.maxHealth <= health_threshold)
 			reduced_spawns = TRUE
 
-	for (var/turf/open/target_turf in oview(7, owner_turf))
+	for (var/turf/open/target_turf in oview(spike_range, owner_turf))
 		if (sqrt((target_turf.x - owner_turf.x) ** 2 + (target_turf.y - owner_turf.y) ** 2) > 9.5) // big circle is a lie
 			continue
 

code/modules/mob/living/basic/lavaland/tendril/tendril_ai.dm

@@ -2,6 +2,8 @@
 	blackboard = list(
 		BB_TARGETING_STRATEGY = /datum/targeting_strategy/basic,
 		BB_TARGET_MINIMUM_STAT = HARD_CRIT,
+		BB_AGGRO_RANGE = 9, // Keeps an eye on you even if you flee
+		BB_AGGRO_GRAB_RANGE = 5, // Only aggros if you get real close and personal
 	)
 
 	planning_subtrees = list(
@@ -22,7 +24,8 @@
 	ability_key = BB_TENDRIL_LASH
 
 /datum/ai_planning_subtree/use_mob_ability/tendril_lash/SelectBehaviors(datum/ai_controller/controller, seconds_per_tick)
-	if (!controller.blackboard[BB_BASIC_MOB_CURRENT_TARGET])
+	var/atom/target = controller.blackboard[BB_BASIC_MOB_CURRENT_TARGET]
+	if (isnull(target) || get_dist(controller.pawn, target) > /obj/projectile/tentacle_lash::range)
 		return FALSE
 	return ..()
 
@@ -30,6 +33,8 @@
 	ability_key = BB_TENDRIL_SPIKES
 
 /datum/ai_planning_subtree/use_mob_ability/tendril_spikes/SelectBehaviors(datum/ai_controller/controller, seconds_per_tick)
-	if (!controller.blackboard[BB_BASIC_MOB_CURRENT_TARGET])
+	var/atom/target = controller.blackboard[BB_BASIC_MOB_CURRENT_TARGET]
+	var/datum/action/cooldown/mob_cooldown/tendril_cross_spikes/ability = controller.blackboard[ability_key]
+	if (isnull(target) || !istype(ability) || get_dist(controller.pawn, target) > ability.spike_range)
 		return FALSE
 	return ..()