Hide concealed Duke execution from Ghola guidance

docs/RULE_DECISIONS.md

@@ -1,5 +1,12 @@
 # Rule decision index
 
+## Concealed Duke and Ghola guidance — 29 October 2026
+
+Ecaz's Ghola guidance uses its projected Duke state, matching ordinary revival;
+authoritative play still validates physical custody. A distinct potential leak
+in Ambassador acquisition availability remains open.
+[Scope](DUKE_VIDAL_RULES.md#concealed-duke-ghola-guidance--29-october-2026).
+
 ## Caladan occupier's auction knowledge — 29 October 2026
 
 The existing Truthtrance auction fact recognizes a successfully inspected