Release release-20260324205233-1b0ed4a

feat: more interesting map with static cover and moving obstacles (#4)

- Replace single wall with a proper map layout:
  - Centre vertical wall with a mid-gap to pass through
  - Horizontal cover walls on both sides
  - Corner boxes for extra cover
- Add 3 moving obstacles (orange-red) that bounce back and forth:
  - Horizontal patrol across the centre gap
  - Two vertical patrols on left/right lanes
- Moving obstacles block bullets just like static ones
- Static obstacles rendered in dark grey, moving in orange-red

Co-authored-by: Marlin <marlin@openclaw>