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.

include/rendering/m2_renderer.hpp

@@ -98,6 +98,7 @@ struct M2ModelGPU {
     std::vector<uint32_t> globalSequenceDurations;  // Loop durations for global sequence tracks
     bool hasAnimation = false;  // True if any bone has keyframes
     bool isSmoke = false;       // True for smoke models (UV scroll animation)
+    bool isSpellEffect = false;  // True for spell effect models (skip particle dampeners)
     bool disableAnimation = false; // Keep foliage/tree doodads visually stable
     bool hasTextureAnimation = false; // True if any batch has UV animation