Eight new spells: seer's eye, cave-in, haste, stoneskin, gold rain, invisibility, plague, quake

- researched in the library (and unlocked in the campaign), in the spells menu with own icons and a radius under the pointer
- haste speeds up everything a creature does, stoneskin halves damage, invisible creatures are ignored by enemies and towers until they attack (drawn see-through), plague spreads among enemies, quake hurts and stuns enemies only, cave-in turns floor back into earth
- particles for every spell

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

src/ui.rs

@@ -158,10 +158,11 @@ pub enum Tool {
     Bridge,
     Steel,
     Trap(crate::traps::TrapKind),
+    Spell(crate::spells::Spell),
 }
 
 // New tools are appended so that existing key bindings ("tool<i>") keep their meaning
-pub const TOOLS: [Tool; 32] = [
+pub const TOOLS: [Tool; 40] = [
     Tool::Dig,
     Tool::Hand,
     Tool::Room(0),
@@ -194,6 +195,14 @@ pub const TOOLS: [Tool; 32] = [
     Tool::Trap(crate::traps::TrapKind::WoodDoor),
     Tool::Trap(crate::traps::TrapKind::IronDoor),
     Tool::Trap(crate::traps::TrapKind::MagicDoor),
+    Tool::Spell(crate::spells::Spell::Eye),
+    Tool::Spell(crate::spells::Spell::CaveIn),
+    Tool::Spell(crate::spells::Spell::Haste),
+    Tool::Spell(crate::spells::Spell::Stoneskin),
+    Tool::Spell(crate::spells::Spell::GoldRain),
+    Tool::Spell(crate::spells::Spell::Invisible),
+    Tool::Spell(crate::spells::Spell::Plague),
+    Tool::Spell(crate::spells::Spell::Quake),
 ];
 
 
@@ -218,6 +227,7 @@ pub fn tool_info(t: Tool) -> ToolInfo {
         Tool::Room(7) => ("aerie", T_AERIE, Some(7)),
         Tool::Room(_) => ("forge", T_FORGE, Some(8)),
         Tool::Trap(k) => (k.id(), I_TRAPS + crate::traps::TRAP_KINDS.iter().position(|&t| t == k).unwrap_or(0) as u32, None),
+        Tool::Spell(sp) => (sp.id(), I_SPELLS + crate::spells::SPELLS.iter().position(|&t| t == sp).unwrap_or(0) as u32, None),
         Tool::Tower(TowerKind::Arrow) => ("arrow", I_ARROW, None),
         Tool::Tower(TowerKind::Cannon) => ("cannon", I_CANNON, None),
         Tool::Tower(TowerKind::Magic) => ("magic", I_MAGIC, None),
@@ -240,6 +250,7 @@ pub fn tool_info(t: Tool) -> ToolInfo {
 // costs that do not depend on the game (bestiary)
 pub fn tool_cost_static(t: Tool) -> String {
     match t {
+        Tool::Spell(sp) => trf("cost.mana", &[(sp.cost() as i32).to_string()]),
         Tool::Trap(k) => trf("cost.work", &[(k.work() as i32).to_string()]),
         Tool::Bridge => trf("cost.bridge", &[BRIDGE_COST[0].to_string(), BRIDGE_COST[1].to_string()]),
         Tool::Steel => trf("cost.steel", &[STEEL_COST[0].to_string(), STEEL_COST[1].to_string()]),
@@ -261,7 +272,7 @@ pub fn tool_cost_static(t: Tool) -> String {
 
 pub fn tool_cost(t: Tool, g: &Game) -> String {
     match t {
-        Tool::Trap(_) => tool_cost_static(t),
+        Tool::Trap(_) | Tool::Spell(_) => tool_cost_static(t),
         Tool::Room(r) => trf("cost.gold_tile", &[ROOM_COST[r].to_string()]),
         Tool::Lightning => trf("cost.mana", &["50".into()]),
         Tool::Heal => trf("cost.mana", &["60".into()]),
@@ -291,7 +302,7 @@ pub const CATS: [(&str, &[usize]); 7] = [
     ("cat.rooms", &[2, 3, 4, 5, 6, 12, 13, 18, 21, 17]),
     ("cat.towers", &[14, 15, 16, 20]),
     ("cat.traps", &[22, 23, 24, 25, 26, 27, 28, 29, 30, 31]),
-    ("cat.spells", &[9, 10, 11]),
+    ("cat.spells", &[9, 10, 11, 32, 33, 34, 35, 36, 37, 38, 39]),
     ("cat.orders", &[8, 7, 19]),
 ];