Connect Semuta with native allied retention

docs/SEMUTA_DISCARD_CONTINUATIONS.md

@@ -1,5 +1,20 @@
 # Semuta discard producers and continuation inventory
 
+## Native Moritani retention and Ixian substitution — 29 October 2026
+
+**Prototyped / Partial.** Fresh Basic Richese games with independent Ecaz
+Treachery Cards can offer an initial mandatory loser discard while a native
+Moritani allied-retention choice is pending. A later discard of the unkept
+played card has its own offer; neither offer includes the retained card or
+replays the battle. The existing Ixian continuation also offers the loser's
+discard before native Suboid/Cyborg substitution and the winner's mandatory
+discard after substitution. The fixtures start with native public setup and
+stage conserved battle forces and card custody, then use the actual decisions.
+Advanced, other optional modules and further reaction combinations remain
+open. The ordering is an online composition, not a publisher priority ruling.
+[Moritani cases](../tests/semuta-independent-native-retention.test.ts);
+[Ixian cases](../tests/semuta-independent-native-substitution.test.ts).
+
 ## Battle and special-card discards with native factions — 29 October 2026
 
 **Prototyped / Partial.** Fresh Basic Richese games with selected native