Add centralized anisotropic filtering, fog, and Blinn-Phong specular to all renderers

Anisotropic filtering now queries GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT once
and applies via a single applyAnisotropicFiltering() utility, replacing
hardcoded calls across all renderers. Fog (sky horizon color, 100-600
range) and Blinn-Phong specular highlights are added to WMO, M2, and
character shaders for visual parity with terrain. Shadow sampling
plumbing (sampler2DShadow with 3x3 PCF) is wired into all three shaders
gated by uShadowEnabled, ready for a future shadow map pass.

include/rendering/wmo_renderer.hpp

@@ -129,6 +129,20 @@ public:
      */
     void setFrustumCulling(bool enabled) { frustumCulling = enabled; }
 
+    void setFog(const glm::vec3& color, float start, float end) {
+        fogColor = color; fogStart = start; fogEnd = end;
+    }
+
+    void setShadowMap(GLuint depthTex, const glm::mat4& lightSpace) {
+        shadowDepthTex = depthTex; lightSpaceMatrix = lightSpace; shadowEnabled = true;
+    }
+    void clearShadowMap() { shadowEnabled = false; }
+
+    /**
+     * Render depth-only for shadow casting (reuses VAOs)
+     */
+    void renderShadow(const glm::mat4& lightView, const glm::mat4& lightProj, Shader& shadowShader);
+
     /**
      * Get floor height at a GL position via ray-triangle intersection
      */
@@ -308,6 +322,16 @@ private:
     bool frustumCulling = true;
     uint32_t lastDrawCalls = 0;
 
+    // Fog parameters
+    glm::vec3 fogColor = glm::vec3(0.5f, 0.6f, 0.7f);
+    float fogStart = 400.0f;
+    float fogEnd = 1200.0f;
+
+    // Shadow mapping
+    GLuint shadowDepthTex = 0;
+    glm::mat4 lightSpaceMatrix = glm::mat4(1.0f);
+    bool shadowEnabled = false;
+
     // Optional query-space culling for collision/raycast hot paths.
     bool collisionFocusEnabled = false;
     glm::vec3 collisionFocusPos = glm::vec3(0.0f);