Room.dark + Item.light flags, a Light helper (isLit/carryingLight), and command
gating: can't enter a dark room without a lit light source; look/take/examine
obscured in the dark; HUD light field wired. Entry-gate prevents soft-locks.
Demo: dark dungeon needs the lit lamp. Fuel/timed light out of scope.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
