Restructure the homepage to lead with visuals instead of text:
- Hero: split layout with animated Tektronix 465 oscilloscope showing
RC step response (CSS+SVG, zero JS) that links to the notebook
- Pipeline strip: 3-step Write → Simulate → Visualize with code/terminal
previews and inline waveform SVG
- Featured notebooks: 3 curated circuits (RC, 555, common emitter) with
pre-rendered waveform thumbnails
- Gallery cards: decorative graticule header strip, color-coded by engine
- Footer: updated copy with clearer call to action
All new sections are server-rendered Astro components. Total new client
JavaScript: zero bytes.
SSR the notebook list in Astro frontmatter (eliminating the client-side
loading spinner). Add hero section with oscilloscope graticule background,
4-column feature highlights, and a React island gallery with category
filter pills, tag search, and grouped/flat view modes.
