Five new rooms: prison, graveyard, guard post, arena, sacrifice altar; new creature: the revenant

- prison: captured heroes sit in cells apart from the torture chamber, do not defect and starve in time; the hand can move prisoners between cells and torture
- graveyard: the fallen are buried there; after a while some rise as revenants (undead: no food, no sleep, life drain from level 5)
- guard post: creatures hold the position and attack whatever comes into view
- arena: creatures spar in pairs for fast, free experience, at the cost of bruises
- sacrifice altar: creatures dropped on it are sacrificed; certain pairs bring a rare creature, otherwise a blessing (mood and mana)
- researched in the library, campaign unlocks, textures, furniture, texts EN/DE, bestiary

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/campaign.rs

@@ -10,7 +10,7 @@ use serde::{Deserialize, Serialize};
 // From which mission (0-based) on each tool is available (same order as ui::TOOLS):
 // dig, hand, treasury, lair, farm, training, library, sell, flag, lightning, heal, imp,
 // torture, temple, arrow tower, cannon tower, magic tower, bridge, aerie, steel
-pub const TOOL_UNLOCK: [usize; 40] = [0, 0, 0, 0, 0, 2, 5, 0, 0, 3, 5, 0, 8, 12, 3, 7, 12, 1, 8, 17, 0, 7, 7, 10, 12, 12, 7, 16, 16, 7, 10, 16, 9, 13, 6, 10, 14, 17, 19, 22];
+pub const TOOL_UNLOCK: [usize; 45] = [0, 0, 0, 0, 0, 2, 5, 0, 0, 3, 5, 0, 8, 12, 3, 7, 12, 1, 8, 17, 0, 7, 7, 10, 12, 12, 7, 16, 16, 7, 10, 16, 9, 13, 6, 10, 14, 17, 19, 22, 9, 13, 6, 11, 18];
 
 pub struct FortDef {
     pub at: (f32, f32), // centre as a fraction of the map size