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/render3d.rs

@@ -2574,6 +2574,11 @@ pub fn minimap_color(tile: &Tile) -> [u8; 4] {
         Kind::ManaSpring => [90, 230, 255, 255],
         Kind::RuneChest => [80, 200, 255, 255],
         Kind::Forge => [150, 70, 40, 255],
+        Kind::Prison => [90, 90, 100, 255],
+        Kind::Graveyard => [70, 90, 60, 255],
+        Kind::GuardPost => [150, 50, 50, 255],
+        Kind::Arena => [200, 170, 110, 255],
+        Kind::Altar => [120, 20, 40, 255],
         Kind::Door => [140, 90, 50, 255],
     }
 }