Hero wave AI: varying entry points facing the gate, split waves, scout warning with directions and minimap markers

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

DESIGN.md

@@ -61,6 +61,22 @@ An original dungeon management game (genre: dungeon building & defence) that run
 - **Spells** (mana): lightning, heal, summon Pit Imp
 - **Heroes**: knight, archer, priest, dwarf miner, paladin of light (they dig their way to the Soul Core)
 
+## Walls, towers, torture, temple
+- **Reinforced walls**: imps reinforce earth walls next to claimed ground automatically (free, lowest priority). Heroes avoid them (path cost ×10) and need ~10× as long to break through; the player's imps need twice as long to dig them out
+- **Defence towers** on claimed floor (one tile, not walkable), three tools; clicking an own tower with the same tool upgrades it (3 levels). Gold for building/upgrading, the magic tower uses mana per shot
+  - Arrow tower: cheap, fast; arrows pierce up to two more heroes
+  - Cannon tower: slow, long range, splash damage with knockback, minimum range
+  - Magic tower: never misses, slows, jumps to a second hero
+  - Heroes attack towers; imps repair them; towers count with half their combat value to the army value
+- **Torture chamber**: one prisoner per 2 tiles. Defeated heroes are knocked out (if there is room) and carried in by imps; torture drains their HP over ~100 s, ~40% defect (paladins ~25%) and become own creatures (needs, wage, lair). Attracts the **Jailer** (6+ tiles): tanky melee that pulls enemies in with a chain
+- **Temple**: creatures pray for mana (more than studying) and mood. Attracts the **Flame Priestess** (6+ tiles): fireballs with splash damage, heals creatures, heals the Soul Core (~8 HP/s) when it is below 90% and no fight is nearby
+
+## Hero wave AI
+- Each wave picks an **entry point** on the border of the realm facing the hero gate: few towers/creatures, no reinforced walls and a short way are attractive, entry points of recent waves are avoided, plus some randomness
+- Waves of **6+ heroes split into two groups** with different entry points (the paladin goes with the bigger group)
+- Heroes first tunnel to their entry point, then go for the core
+- **Warning** 30 s before: scout message with the direction(s) and blinking markers on the minimap
+
 ## Goal
 - **Victory**: destroy the Hero Gate
 - **Defeat**: the Soul Core is destroyed