Support unused selected decks with Nexus and Discovery

docs/NEXUS_CARD_RULES.md

@@ -2,6 +2,20 @@
 
 Original source audit, 10 September 2026, with dated bounded runtime follow-ups below. This document establishes the printed component inventory, source protocol and implementation boundaries; none lifts expansion release gates. The ordinary worm-triggered alliance Nexus already in the engine is distinct from this optional card module.
 
+## Selected decks without independent cards — 29 October 2026
+
+**Prototyped / Partial.** Fresh Basic and Advanced Nexus previews can select
+original expansion decks without the independent Ecaz cards when at least one
+selected family has no seated native faction. Discovery may also be selected.
+Existing seat and module prerequisites remain; Leader Skills and Advanced
+Harkonnen with Ecaz or Moritani retain their separate boundaries. Ecaz Occupy,
+Moritani assassination and their shared arrival use their existing handlers.
+
+Public-start fixtures cover classic and native seats, original selected card
+stock, a real worm-triggered alliance and Nexus draw, and a Richese card spent
+on shipment. They control unopened deck order. These cases do not establish
+complete games or all card and module interactions; deployed proof remains open.
+
 ## Independent cards with Discovery — 18 October 2026
 
 **Prototyped / Partial.** The independent three-card variant now composes with