Give room tiles configurable hit points per room type

[Upabjojr]

Proposal 2 of the set following the mechanics discussion in #23 (#23 (comment)) — the "rooms destructible" side of the "claimable or destructible" question.

Rooms are in fact already destructible today: enemy fighters (not workers) target visible enemy rooms, damage them tile by tile, and a tile at 0 HP is removed from the room — with the recently merged room splitting (#23) even cutting a room in two. But every tile of every room has a flat Building::DEFAULT_TILE_HP = 10.0, which a mid-level creature removes in a couple of swings, and there is no way to tune it. As a mechanic it exists but has no knobs.

This PR gives it knobs: Room::getTileHP() reads <RoomName>HP from rooms.cfg (e.g. DormitoryHP, TreasuryHP, DungeonTempleHP), falling back to the old 10 when an entry is missing, so older config files keep working. Shipped defaults make rooms meaningfully sturdier than a creature (30–50 HP per tile, 100 for the dungeon temple) — first-guess numbers, meant to be argued about in the config file rather than in code.

Notes for the design discussion:

• A destroyed room tile stays claimed by its old owner (Building::removeCoveredTile does not unclaim), so the owner can rebuild on it cheaply, while the attacker would still have to dance the ground afterwards. Destruction is therefore already less "permanent" than it sounds — the owner loses the building and half the gold, not the territory.
• Repair (Room::repairRoom) is currently only ever called by the AI keeper; human players just re-buy tiles. Making repair a player action could be a follow-up if the destructible route is chosen.

This proposal is independent of the others in the set: it can be merged alone, together with the traps one (#32), or alongside the claimable-rooms prototype — the mechanics compose (some rooms could be claimable and all of them destructible, DK2-style).

Validated: builds and the full test suite passes via ctest.

🤖 Generated with Claude Code

[Upabjojr]

Pushed 19ae3288 following the discussion on #32: <RoomName>HP = 0 now means the room is indestructible — Room::isAttackable refuses targets on it, and a Room::takeDamage override shields it from stray damage that bypasses target selection (rolling boulders, area effects). Internally its tiles keep positive HP, since zero HP means "tile destroyed" everywhere else. Documented in rooms.cfg.

So both camps of the "claimable vs destructible" question are now a config choice per room type: 0 = reclaim-only, any positive value = attackable with that many hit points per tile.

🤖 Generated with Claude Code