Website: Wheel of the Year seasonal themes with auto-midnight updates

Colour themes now follow the Wheel of the Year. Eight seasonal themes map to the eight sabbats, replacing the previous four-theme rotation.

Seasonal themes (new "Wheel of the Year" category):

Sabbat	Dates	Theme	Colour
Samhain	Oct 31 – Nov 1	Ocean	deep blue
Yule	Dec 20–23	Slate	dark cold grey
Imbolc	Feb 1–2	Frost	pale ice-blue
Ostara	Mar 19–21	Sage	green
Beltane	Apr 30 – May 1	Ember	fire-red
Litha	Jun 20–22	Amber	bright gold
Lughnasadh	Aug 1–2	Copper	harvest orange
Mabon	Sep 21–24	Rust	earthy brown-red

Between-sabbat periods use the season in force — no jarring jumps mid-cycle.

Auto-midnight updates: If a user leaves the page open at midnight and the date has crossed into a new sabbat or period, the theme updates automatically (every 60s check). Tick stops the moment they pick an explicit theme.

website bumped: 11.11.1 → 11.12.0

Part of the @ewanc26/pkgs monorepo.