Build interactive VanSpace orbit experience

[fenner888]

What changed

• Replaces the static landing hero with the interactive VanSpace poster-to-orbit experience.
• Uses the Space Centre artwork as runtime-dithered particles, with scroll-driven release, draggable orbital bodies, meteors, and a click/keyboard wormhole transition into the speaker section.
• Keeps the opening poster composition responsive, with a three-line event proposition and fine particle halo on desktop and mobile.
• Moves the rest of the page into a denser editorial conference layout and adds the film placeholder, wider agenda/about/ticket sections, share metadata, and canonical URL.
• Applies the off-white keyboard / blue-screen palette and updated VanSpace marks, while keeping Cognition as a small floating sponsor tag.
• Removes the unreferenced stipple.js and space-centre-pixel.jpg files.

Why

The repository already contained the core orbit idea, but it was not wired into the shipped page. The live hero was therefore a static image even though the interactive poster-to-system transition is the event's most distinctive visual idea. This connects that interaction and gives the supporting conference content a clearer, more compact hierarchy.

Validation

• node --check site/orbit-hero.js
• git diff --check
• Balanced CSS braces, HTML div elements, and HTML section elements
• Confirmed deleted assets have no remaining references
• Browser-tested the committed branch at 1440×900 and 390×844
• Confirmed three-line hero title, no horizontal overflow, and no console warnings or errors at both widths
• Verified reduced-motion and image-failure fallbacks remain in the implementation

Before merge

• Run a physical iPhone and Android device pass for scroll feel, touch rotation, label placement, and wormhole timing.
• Replace the film placeholder when the sizzle asset is ready.
• Confirm the event date and ticket-opening language.