Block scripts and triggers: data model, Rhai translation and runtime

Editor missions keep a painted map or roll a random map per campaign run,
leave out goals they cannot have, and run their triggers in the fixed step.

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

src/spells.rs

@@ -86,6 +86,7 @@ impl Game {
             self.sfx_ui(Sfx::Error);
             return;
         }
+        self.script_event(crate::mscript::ScriptEvent::Spell(crate::mscript::spell_name(spell)));
         let r2 = spell.radius() * spell.radius();
         let near = |e: &Ent| (e.x - wx).powi(2) + (e.y - wy).powi(2) < r2;
         match spell {