Teleportationstrank: yellow potions open the portal window

- Every yellow potion (potion kind 5, all stages) is a Teleportationstrank:
  drinking it posts the teleporter's event to the busy dialog with the
  hero's known portals; the potion is used up only when the hero teleports
  from that window (closing it keeps the potion)
- Names replaced in every game text (ReplaceInTexts), so item names and the
  bottom bar's quick-select tooltip read Teleportationstrank; GameText reads
  the game's own text
- HeroIndex / HeroInventory moved to skillslots for shared use
- docs/teleport-potion.md; walking animation after loading noted in todo

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

CMakeLists.txt

@@ -62,6 +62,7 @@ add_library(sacred_re SHARED
     src/mods/megamap.cpp
     src/mods/respec.cpp
     src/mods/runetrade.cpp
+    src/mods/teleportpotion.cpp
     src/mods/guards.cpp
 )
 target_include_directories(sacred_re PRIVATE src)