Enable advanced mixed-faction paired arrivals

tests/deferred-movement-arrival-recovery.test.ts

@@ -37,7 +37,9 @@ async function fixture(t: test.TestContext) {
     ornithopter: 'range3',
   });
   assert.equal(game.decision?.kind, 'choamMovement');
-  // Restore the checkpoint's legacy topology after its genuine unspent declaration.
+  // Restore an unsupported legacy Semuta topology after its genuine
+  // unspent declaration; the ordinary mixed-faction profile is now supported.
+  game.semutaPreview = true;
   addArrivalTerror(game);
   game.version = 31;
   const pending = arrivalReload(game),