fix(camera): NaN-safe getRight/getUp when forward ~= world up

If forward is parallel to (0,0,1) — camera staring straight up or
down — the cross product is zero and glm::normalize returned NaN.
That NaN flowed into glm::lookAt and produced a NaN view matrix.

The editor camera clamps pitch to +/-89 so it doesn't trigger,
but other call sites or scripted test paths could construct a
Camera at +/-90 and immediately blow up. Length-check the cross
and fall back to world +X / +Z.

src/rendering/camera.cpp

@@ -39,12 +39,20 @@ glm::vec3 Camera::getForward() const {
 }
 
 glm::vec3 Camera::getRight() const {
-    // Use Z-up for WoW coordinate system
-    return glm::normalize(glm::cross(getForward(), glm::vec3(0.0f, 0.0f, 1.0f)));
+    // Use Z-up for WoW coordinate system. If forward is parallel to the up
+    // axis (camera staring straight up/down), cross is zero and normalize
+    // returns NaN — fall back to world +X so view/proj stay finite.
+    glm::vec3 c = glm::cross(getForward(), glm::vec3(0.0f, 0.0f, 1.0f));
+    float len = glm::length(c);
+    if (len < 1e-6f) return glm::vec3(1.0f, 0.0f, 0.0f);
+    return c / len;
 }
 
 glm::vec3 Camera::getUp() const {
-    return glm::normalize(glm::cross(getRight(), getForward()));
+    glm::vec3 c = glm::cross(getRight(), getForward());
+    float len = glm::length(c);
+    if (len < 1e-6f) return glm::vec3(0.0f, 0.0f, 1.0f);
+    return c / len;
 }
 
 void Camera::setJitter(float jx, float jy) {