Enable Basic Nexus Kull and native reactions

docs/NEXUS_CARD_RULES.md

@@ -877,6 +877,24 @@ the Cheap Hero identity. Other rosters, nested effects, complete games and
 deployed acceptance remain open. The later public Semuta entry below removes
 the stated Emperor and Sapho blockers for its narrower CHOAM-only Basic scope.
 
+## Basic native Nexus reactions and Kull — 30 October 2026
+
+**Prototyped / Partial.** Fresh Basic Nexus games with selected Ix and/or
+CHOAM decks and no other modules initialize their native reactions even when
+every selected family is seated. Harkonnen's existing Betrayal can follow an
+actual matching call in those games, including the supported CHOAM/Richese
+Semuta start; Use or Pass retains the original battle and Mentat continuation.
+Ixian and Guild reactions retain their native setup and controls.
+
+Fresh Basic CHOAM/classic Nexus games with the Ix and CHOAM decks now enable
+the existing source-aware Kull preview by default, with the normal host opt-out.
+The physical Sandtrout remains in the Ix Spice deck. A public journey exercises
+printed and Nexus-fueled Kull after drawing Sandtrout, including decline and a
+distinct counter. Card order, custody, force positions and an earned Nexus
+identity are staged; setup and actions are real. The existing provisional
+counter and response ordering remains. Richese/Kull, other modules, broader
+nested reactions, full games and deployed acceptance remain open.
+
 ## Basic public Semuta and Nexus — 30 October 2026
 
 **Prototyped / Partial.** A fresh Basic Richese game with the CHOAM deck,