Teleportationstrank: the running campaign's portal list

In the Underworld the potion opens the Underworld portals (busy dialog mode
6, as the teleporters there do); g_campaign moved to game/addresses.h.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

src/mods/characters.cpp

@@ -43,6 +43,7 @@
 
 #include <windows.h>
 
+#include "game/addresses.h"
 #include "game/engine/events.h"
 #include "game/engine/objects.h"
 #include "game/ui/draw.h"
@@ -102,7 +103,7 @@ constexpr uintptr_t kGameLevel = 0x0182cdc4;  // g_gameLevel: the difficulty of
 // g_campaign (u16): the campaign of the game to start / running. The main menu
 // sets it by entry (0x712180..), cEngine::Load from the save header; the load
 // window lists only saves of it (0x71e2b9).
-constexpr uintptr_t kCampaign = 0x0182cdc8;
+constexpr uintptr_t kCampaign = game::addr::g_campaign;
 constexpr size_t kSessionSinglePlayer = 0x14;  // set to 1 by both
 constexpr size_t kSessionHeroClass = 0x44;     // the start hero's class (Session::SetHeroClass 0x7d7cf0)
 // cCommand_armaPlay (vtable 0x894ff4): execute (0x755ac0) posts 0x8002 (mode,