Redesign landing site with light/dark mode and interactive visualizations

[pranavp311]

Summary

• Light/dark mode: Light mode as default with a toggle button in the navbar. Dark mode persists via localStorage. All pages, canvas components, and code blocks adapt to the active theme.
• Interactive 3D VectorBadge: Physics-based rotating vector lines with depth sorting, smooth mouse tracking, and hover effects. Replaces the old architecture diagram.
• TypewriterText: Headline cycles "Evolution is here." → "Evolution is emergent." with a blinking cursor that persists after completion.
• PerformanceRace: Animated horizontal bar comparison (EmergentDB vs ChromaDB vs LanceDB) with scale selector (1K/10K/50K), speedup callouts, and recall stats.
• CodeBlock: VS Code Dark+ syntax highlighting for Rust and shell code. Used on home page and all docs code blocks.
• Page transitions: Smooth fade-in + slide-up animation on route changes via Framer Motion.
• Smooth scrolling: CSS scroll-behavior: smooth on the html element.
• Hero stats row: <1ms latency, 9.6/10 RAG quality, 12M/s inserts, 1M vectors tested.
• Background particles: Theme-aware RetrievalViz with increased visibility and mouse-proximity connecting lines.
• Removed: ArchitectureDiagram, BenchmarkBar, BenchmarkRunner, Vercel analytics packages.

Test plan

• cd frontend && bun run build compiles all 5 routes with 0 errors
• Light mode renders correctly on all pages
• Dark mode toggle works and persists across page reloads
• TypewriterText types "here.", deletes, types "emergent.", stops with blinking cursor
• VectorBadge rotates, responds to mouse, adapts colors in dark mode
• PerformanceRace bars animate on scroll, scale tabs re-trigger animation
• Code blocks show syntax highlighting on home and docs pages
• Page transitions animate smoothly between routes
• Background particles visible and interactive in both themes