Add four Star Trek / Lower Decks pages with a 3D printer red alert

LCARS ship status, the Cerritos duty roster from the agenda, a warp core
driven by solar power with Rutherford's advice, and a captain's log under
a viewscreen. Original pixel art in tools/trek_sprites.py.

When the 3D printer (Moonraker current_print_state, `printer`
substitution) is paused or in error, the panel jumps to LCARS Status in
red alert and holds the rotation until it carries on.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

components/el512/el512_pages.h

@@ -33,6 +33,7 @@ struct HomeData {
   float grid{NAN};         // W, > 0 = import
   std::string agenda;      // sensor.el512_agenda events: "day|time|title;..."
   std::string message;     // the panel's Message text
+  std::string printer;     // 3D printer state (Moonraker: printing, paused, error, ...)
   Reading rooms[4];
 
   // Today's solar power in 15-minute slots (highest value seen per slot; -1 =