Traps and doors made in a new forge room, installed by imps; new creature: the cogling

- forge room: creatures work there (coglings fastest), the work goes into the oldest planned trap or door; finished pieces wait as crates, imps carry and install them
- traps: spike pit, poison vent (cloud), fire jet, stone roller, alarm bell (calls creatures), rune mine (one big blast), frost glow (slows around it)
- doors: wood, iron, magic (hurls attackers back); own creatures pass, enemies smash them on their way; clicking a door with a door tool locks it for everybody
- new 'Traps' category in the toolbar, forge in the rooms; texts EN/DE, bestiary entries; atlas grown for new textures and icons
- tests: forge to installed trap, spikes hurt, doors lock and get smashed

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

src/map.rs

@@ -61,6 +61,8 @@ pub enum Kind {
     Steel,      // steel wall: hardly anyone gets through
     ManaSpring, // crystal spring: once claimed, more mana and a higher mana maximum
     RuneChest,  // dwarven chest with the plans of a rune forge tower (claim it: one free build)
+    Forge,      // room: creatures manufacture traps and doors
+    Door,       // floor with an installed door (res bit 0: locked)
 }
 
 // options for the map generator (campaign missions)
@@ -89,7 +91,7 @@ pub struct River {
 }
 
 // order matters for the packed savegame codec: only append new kinds
-const KINDS: [Kind; 27] = [
+const KINDS: [Kind; 29] = [
     Kind::Rock,
     Kind::Earth,
     Kind::Gold,
@@ -117,6 +119,8 @@ const KINDS: [Kind; 27] = [
     Kind::Steel,
     Kind::ManaSpring,
     Kind::RuneChest,
+    Kind::Forge,
+    Kind::Door,
 ];
 
 // treasures (veins, treasury content, imp loads): 0 gold, 1 silver, 2 ruby, 3 diamond
@@ -213,6 +217,8 @@ impl Tile {
                 | Kind::Aerie
                 | Kind::ManaSpring
                 | Kind::RuneChest
+                | Kind::Forge
+                | Kind::Door
         )
     }
     // river tiles (open, but nobody can walk there)
@@ -642,7 +648,15 @@ impl Map {
     }
 
     pub fn walk_cost(&self) -> impl Fn(usize) -> Option<u32> + '_ {
-        move |i| if self.t[i].walkable() { Some(1) } else { None }
+        move |i| {
+            let t = &self.t[i];
+            // a locked door stops the dungeon's own creatures too
+            if t.walkable() && !(t.kind == Kind::Door && t.res & 1 == 1) {
+                Some(1)
+            } else {
+                None
+            }
+        }
     }
 
     // flying creatures also cross water and lava
@@ -663,6 +677,7 @@ impl Map {
                 Kind::Earth => Some(7),
                 Kind::Gold | Kind::Silver | Kind::Ruby | Kind::Diamond => Some(12),
                 Kind::Rock | Kind::Core | Kind::Tower | Kind::Water | Kind::Lava => None,
+                Kind::Door => Some(10),
                 _ => Some(1),
             }
         }