Use object->position instead of the archway tile position when reporting
door locations in FindFirstClosedDoorOnWalkPath and
FindFirstTrackerPathBlock. Archway tiles (negative dObject refs) resolve
to the parent door object, but the returned position was the archway
tile rather than the door itself, causing the player to stop one tile
short.
Also: move DOOR_CLOSED/DOOR_OPEN/DOOR_BLOCKED enum from objects.cpp to
objects.h so diablo.cpp can use the canonical constants directly instead
of maintaining duplicate constexpr values. Add static_assert for
MAXOBJECTS fitting in int8_t, defensive assertions in AddDoor(), and
clarify comments around door state checks.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
hidwood
Eric Robinson
Gleb Mazovetskiy