Fix AdventureBot group preparation, public portals and flight recovery

Add preparation outings and equipment checks with a five-minute return to the meeting point. Correct static portal visitor casting and level conditions, with native interaction diagnostics. Recover suspended flying mounts, walk to verified takeoff sites, and validate landing and return volumes. Include SQL migrations, targeted regression tests and live validation checkpoints.

tests/clientless/test_adventure_intent_state.py

@@ -70,6 +70,7 @@ public:
  bool Allowed(Player*,AdventureLocation const&,std::string const&){return true;}
  bool AdoptGroup(Player*,Player*){return false;}
  bool UpdateNavigationRescue(Player*,Record&){return false;}
+ bool UpdateGathering(Player*,Record&,time_t){return false;}
  void Update(Player*,uint32);
  void EnterPlayerInstance(Player*);
  void Generate(Player*,Record&,uint32){}