Add 3D level-up effect using LevelUp.m2 spell model

Replace 2D screen-space ding rings with real WoW LevelUp.m2 particle/geometry
effect. Fix FBlock particle color parsing (C3Vector floats, not CImVector bytes)
which was producing blue/red instead of golden yellow. Spell effect models bypass
particle dampeners, glow sprite conversion, Mod→Additive blend override, and all
collision (floor/wall/camera) to prevent camera zoom-in. Other players' level-ups
trigger the 3D effect at their position with group chat notification. F7 hotkey
for testing.

CMakeLists.txt

@@ -195,6 +195,7 @@ set(WOWEE_SOURCES
     src/rendering/world_map.cpp
     src/rendering/swim_effects.cpp
     src/rendering/mount_dust.cpp
+    src/rendering/levelup_effect.cpp
     src/rendering/loading_screen.cpp
     src/rendering/video_player.cpp