Respect storm sector for rides into mobile stronghold

docs/RULE_DECISIONS.md

@@ -1,5 +1,17 @@
 # Rule decision index
 
+## Worm rides into the mobile stronghold — 29 October 2026
+
+The [publisher FAQ, p. 5](https://www.gf9games.com/dune/wp-content/uploads/2020/11/Dune-FAQ-Nov-2020.pdf)
+allows Fremen to ride directly into the Hidden Mobile Stronghold when the
+destination sector is clear of storm. The game represents its interior as
+sector zero; this implementation maps that check to the stronghold's actual
+pointing sector. That mapping is an online interpretation of the FAQ, while
+forces already inside retain the printed storm shelter. Ordinary, Cunning and
+Great Maker rides share this destination check; Polar Sink remains clear.
+[Shared quote](../game/worm-ride-destination.ts),
+[runtime cases](../tests/worm-ride-mobile-storm-runtime.test.ts).
+
 ## Basic leaderless battle announcement — 29 October 2026
 
 The [publisher base rulebook, printed p. 10](https://www.gf9games.com/dunegame/wp-content/uploads/Dune-Rulebook.pdf)