- New 3×2 building placeable only on ROCK tiles without resources (50 stone + 200 wood)
- Mine entrance at bottom-centre tile (tileX+1, tileY+1) — only passable tile
- Other 5 footprint tiles blocked via resourceTiles index (impassable ROCK)
- Nisse with mine priority > 0 walk to entrance, hide inside for MINE_WORK_MS (15 s),
then reappear carrying MINE_STONE_YIELD (2) stone and haul to stockpile
- Up to MINE_CAPACITY (3) Nisse work simultaneously; overflow Nisse wait for a slot
- ⛏ X/3 world-space status label above building updated each frame
- Surface rock harvesting unchanged; mine buildings take precedence in pickJob
- Ghost resizes to 3×2 when mine is selected; placement validated across full footprint
- Mine added to build menu with cost and placement hint
Closes#42
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
