Auto-attack: next target, melee/ranged rule after arts; chain range = cast range

- autoattack: when the target dies, the nearest enemy within close range
  (contact distance + a step) takes over; after an art the hero auto-attacks
  if the art was melee (walked up / cast close by), or ranged with a ranged
  weapon, or ranged with an enemy already in melee range; measured action
  codes and weapon classes in game/engine/orders.h
- chainlightning: jumps reach Blitzschlag's cast range (20 ray segments of
  30, the art code's hit check) via the shared NearestHostile search
- guards: burning bone render hook had the wrong signature (device plus a
  4x4 matrix by value, ret 0x44) and corrupted the stack when fire arrows hit
- crash reports follow the ebp chain before the raw stack scan

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

src/mods/guards.cpp

@@ -13,9 +13,13 @@ namespace game {
 // pressed while walking; Windows reported sacred.exe+0x374e39). Who renders
 // it without a device is not known yet (sacred_re_crash.txt will tell). With
 // no device there is nothing to draw.
-void __fastcall BurningBone_Render(void* self, void* edx, void* device);
+// (device, a 4x4 matrix by value; ret 0x44).
+struct Matrix4 {
+    float m[16];
+};
+void __fastcall BurningBone_Render(void* self, void* edx, void* device, Matrix4 transform);
 RE_HOOK(0x00774e10, BurningBone_Render);
-void __fastcall BurningBone_Render(void* self, void* edx, void* device) {
+void __fastcall BurningBone_Render(void* self, void* edx, void* device, Matrix4 transform) {
     if (!device) {
         static bool logged = false;
         if (!logged) {
@@ -24,7 +28,7 @@ void __fastcall BurningBone_Render(void* self, void* edx, void* device) {
         }
         return;
     }
-    BurningBone_Render_original(self, edx, device);
+    BurningBone_Render_original(self, edx, device, transform);
 }
 
 } // namespace game