Restore aura visuals after loading a save

Saving marks effect objects dead, so after a load the Heldenmut /
Klingenblick buff was active but its aura effect (cObjectFX 842) was
gone. A few ticks after a save game has loaded, the effect is created
again for each such buff of a player hero (CreateAt + cEventFX 0x42,
as the art's cast effect does), with the buff's remaining time.

Shared game events (game/engine/events): engine tick and "save game
loaded" callbacks; the WASD mod uses the tick through it.

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

CMakeLists.txt

@@ -31,6 +31,7 @@ add_library(sacred_re SHARED
     src/re/sacred_re.def
     src/game/engine/log.cpp
     src/game/engine/cmdline.cpp
+    src/game/engine/events.cpp
     src/mods/borderless.cpp
     src/mods/widescreen.cpp
     src/mods/hud.cpp
@@ -41,6 +42,7 @@ add_library(sacred_re SHARED
     src/mods/inventory_save.cpp
     src/mods/skillbar.cpp
     src/mods/arttarget.cpp
+    src/mods/aura_restore.cpp
 )
 target_include_directories(sacred_re PRIVATE src)
 target_compile_options(sacred_re PRIVATE ${SACRED_RE_CXX_FLAGS})