Got the galaxy running and then couldn't see it — black screen, no errors, 100K particles rendering into the void. React 18 StrictMode double-mounts components, so the useEffect in Scene.tsx created two WebGL renderers and appended two <canvas> elements to the same container ref. The second canvas stacked on top of the first, opaque black, hiding everything. Fix was three lines: clear the container's children before appending the new renderer. While I was in there, found OrbitControls and the singularity mesh weren't getting disposed on unmount — a memory leak that would compound if the user navigated away and back. After the StrictMode fix and cleanup pass: full galaxy rendering, all 7 slider controls live (rotation speed, entropy, spectrum shift, spiral twist, star mass, bloom strength, singularity depth), warp drive engaging with camera shake, FOV distortion, and mouse-steerable tunnel. Zero console errors, clean production build.