The architecture map on phones, and a dark-only site

Written 2026-09-27 as a catch-up entry (Project Manager's decision). This shipped in v0.1.28 to v0.1.30 on 2026-09-21. The screenshot is of the live site today, at 390 px.

• On a phone the desktop map shrank to about 6 px text. Phones first got a vertical list of the parts, then the ring redrawn at phone width with names at about 12.5 px. The final version sets the seven parts in four rows around the center with the same 18 px gap between neighbors.
• The site is dark only. The light theme and the switch that followed the device setting were removed, and the 404 page was fixed to match.