fix(pbr): use clamp instead of reinhard

Author: AhmedAmrNabil

assets/shaders/pbr.frag

@@ -217,8 +217,8 @@ void main() {
 
     vec3 result = ambient + Lo + emission;
 
-    // Reinhard tone-mapping (HDR → LDR) then gamma-encode for display
-    result = result / (result + vec3(1.0));
+    // Clamp tone-mapping (HDR → LDR) then gamma-encode for display
+    result = clamp(ambient + Lo + emission, 0.0, 1.0);
     result = pow(result, vec3(1.0 / 2.2));
 
     // Alpha: sample from texture if present, otherwise use tint/vertex alpha