Ironforge Great Forge lava, magma water rendering, LavaSteam particle effects

- Add magma/slime rendering path to water shader (fbm noise, crust/molten/core coloring)
- Fix WMO liquid height filter rejecting high-altitude zones like Ironforge (Z>300)
- Allow interior WMO magma/slime MLIQ groups to load (skip only water/ocean)
- Mark LAVASTEAM.m2 as spell effect for proper additive blend, hide emission mesh
- Add isLavaModel flag for M2 ForgeLava/LavaPots UV scroll fallback
- Add isLava material detection in WMO renderer for lava texture UV animation
- Fix WMO material UBO colors for magma (was blue, now orange-red)

include/rendering/m2_renderer.hpp

@@ -119,6 +119,7 @@ struct M2ModelGPU {
     bool isElvenLike = false;       // Model name matches elf/elven/quel (precomputed)
     bool isLanternLike = false;     // Model name matches lantern/lamp/light (precomputed)
     bool isKoboldFlame = false;     // Model name matches kobold+(candle/torch/mine) (precomputed)
+    bool isLavaModel = false;       // Model name contains lava/molten/magma (UV scroll fallback)
     bool hasTextureAnimation = false; // True if any batch has UV animation
 
     // Particle emitter data (kept from M2Model)