feat: add missing force field, jetpack NPC and Skullkin volume scripts

Ported from the live server scripts that ship with the client:

- scripts\ai\LS\ForceFieldEffect.lua (LEGO Club and Starbase 3001 force
  fields): plays effect 3671 "cast" on whatever touches the phantom.
- scripts\ai\NP\L_NPC_NP_JETPACK_GUY.lua (jetpack ambient NPCs): plays
  the object's "launch" effect when used.
- scripts\02_server\Map\AM\L_SKELETON_SPAWNER_VOLUME.lua (Crux Prime
  Skullkin area): with 10 or more players in the volume the Skullkin
  engineer, miner and patroller networks maintain 2/6/6 instead of
  1/4/4, with a 60 second cooldown between changes and a catch-up check
  when it ends. Only players are counted, and the count never goes
  below zero.

WBL_Enemy_Grabbler.lua only sets wander variables for the old Lua
movement AI, so it joins the other alpha wander scripts in the excluded
list instead of logging as missing.

Refs #746

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

dScripts/ai/GENERAL/CMakeLists.txt

@@ -1,4 +1,5 @@
 set(DSCRIPTS_SOURCES_AI_GENERAL 
+	"ForceFieldEffect.cpp"
 	"InstanceExitTransferPlayerToLastNonInstance.cpp"
 	"LegoDieRoll.cpp")
 

dScripts/ai/GENERAL/ForceFieldEffect.cpp

@@ -0,0 +1,10 @@
+#include "ForceFieldEffect.h"
+
+#include "Entity.h"
+#include "GameMessages.h"
+
+void ForceFieldEffect::OnCollisionPhantom(Entity* self, Entity* target) {
+	if (!target) return;
+
+	GameMessages::SendPlayFXEffect(target, 3671, u"cast", "", LWOOBJID_EMPTY);
+}

dScripts/ai/GENERAL/ForceFieldEffect.h

@@ -0,0 +1,8 @@
+#pragma once
+#include "CppScripts.h"
+
+// Plays a sparkle effect on anything that touches this phantom physics object.
+class ForceFieldEffect : public CppScripts::Script {
+public:
+	void OnCollisionPhantom(Entity* self, Entity* target) override;
+};

dScripts/ai/NP/CMakeLists.txt

@@ -1,4 +1,5 @@
 set(DSCRIPTS_SOURCES_AI_NP 
+	"NpcNpJetpackGuy.cpp"
 	"NpcNpSpacemanBob.cpp")
 
 add_library(dScriptsAiNP OBJECT ${DSCRIPTS_SOURCES_AI_NP})

dScripts/ai/NP/NpcNpJetpackGuy.cpp

@@ -0,0 +1,9 @@
+#include "NpcNpJetpackGuy.h"
+
+#include "Entity.h"
+#include "GameMessages.h"
+
+void NpcNpJetpackGuy::OnUse(Entity* self, Entity* user) {
+	// No effect ID, the client plays the object's own effect of this type.
+	GameMessages::SendPlayFXEffect(self, -1, u"launch", "", LWOOBJID_EMPTY);
+}

dScripts/ai/NP/NpcNpJetpackGuy.h

@@ -0,0 +1,8 @@
+#pragma once
+#include "CppScripts.h"
+
+// Plays the launch effect when a player talks to the jetpack NPC.
+class NpcNpJetpackGuy : public CppScripts::Script {
+public:
+	void OnUse(Entity* self, Entity* user) override;
+};