feat: Optical Research Console with static infinite archive

[lightsofapollo]

Summary

• shifts the visual language from an editorial journal to an Optical Research Console
• keeps every Markdown/MDX entry as independently generated static HTML
• server-renders the newest 12 archive entries for first paint and SEO
• emits immutable static cursor manifests under /journal/<cursor>.json
• progressively appends pages with IntersectionObserver plus an accessible Load More fallback
• uses content-visibility: auto and intrinsic sizing for browser-native offscreen virtualization
• loads all remaining manifests before applying a lane filter, so filtered results are complete
• provides /archive/ as a complete no-JavaScript static index
• formalizes the visual system in a Google DESIGN.md-compatible token spec

Verification

• DESIGN.md lint: 0 errors, 0 warnings
• npm run check
• npm run build (26 static routes with the committed archive)
• npm test (pagination and build-contract coverage)
• npm run design:audit (clean)
• WebKit desktop, dark-mode, and mobile visual passes
• Browser exercised initial 12-row payload → complete infinite load
• Filtering loaded the complete archive before applying the filter
• Static post, static archive, and cursor manifest returned HTTP 200
• No viewport overflow or browser console errors

Design posture

Primary surface: Monitor. The system should feel like a calibrated research instrument without turning long-form reading into neon-on-black sci-fi UI.

This remains a draft for team review; no auto-merge.