docs(website): add animated architecture diagrams

[enixCode]

What

Three custom animated SVG/React figures for the docs, in the light-* design (icy-blue on near-black, Fraunces + JetBrains Mono), framed as diagram panels so they read the same in light and dark Fumadocs themes.

• Architecture - the 3-tier delegation chain (light-process -> light-run -> light-runner -> Docker), request token down / result token up. In Overview + Execution.
• Dag - the flagship workflow graph: fan-out + a conditional when link. In Workflows.
• NetworkServices - the proxy/secret pattern: the key stays in the proxy, the workload reaches it by hostname. In the Services section.

Why

The docs explained the model in prose; these give the three core concepts a visual anchor. Same stack as the other light-* sites, additive only.

Notes

• Pure CSS animation, no client JS, so they survive the Next static export and honour prefers-reduced-motion.
• Tokens are hardcoded in diagrams.module.css (the landing CSS variables are not in scope inside the docs).
• npx tsc --noEmit passes; the Next build is the CI oracle (Google Fonts fetch fails offline).

build with cc