Adds a Code Animations catalog section — 9 self-contained, installable blocks:
morph, snippet-flight, typing, diff, highlight, scroll (DOM/GSAP) and 3d-extrude,
shader-dissolve, particle-assemble (WebGL). Each block ships only its own effect and
renders deterministically (paused GSAP timeline seeked per frame, seeded RNG, no
render-time data fetch). Wires the catalog nav, registry.json, a new code-animation
Studio category, and preview assets.